I look at forms / kata a little differently.
Assume each technique (punch, block, push, throw, lock...) is a circle. Now, you are going to make a ven diagram with a bunch of those circles. If you pick the right punch, block, push, parry, throw and lock circles... your ven diagram will have something like 80% of the area shared between the circles you chose. (if you pick the wrong circles, you can get very little area shared)
So, if you get two ven diagrams, each consisting of their own sets of technique circles, such that each diagram has 80% or more shared area... then if you practiced one technique from the first and transitioned to one technique from the second... its like you are practicing all of the first set of techniques together, and then transitioning to all of the techniques in the second set. So then, in application, you could pick any of the first set and then go into any of the second set.
You do have to remember, that only about 80% is shared. The other 20% needs to be practiced. Which could be why this one is a "block" and this one is a "punch." That way you are also getting your block, punch, parry.... practice in as well.
Additionally, the 80% of shared area for the set of techniques, is not a random 80%, but rather the most important 80%. The 20% that you have to change, to change a block into a punch, is the least important 20% of the technique. Yes, I realize that your fist has to take a slightly different path and strikes with a slightly different surface when blocking verses striking. But, if you have not developed the power, the speed, the structure, the connection to the ground... then shape of your fist is not really that important... as there is no power to deliver anyway.
So if you think of the form or kata as how to move from this set of techniques to the next set to the next set... now, there is a ton of stuff to look at.
Now, if I wanted to just practice the techniques and "shadow box" with them or drill with them... that works too. But, if you are trying to pass on all the things you learned to a large group of people, who will be instructors of many more people... you will notice that different people like different combinations. Each of your instructors will teach their favorites and each student will concentrate on their favorites. By making people do set forms or kata, you maintain all the patterns and combinations. Those things remain for future students to rediscover. When they do rediscover it... they already know how it fits into everything else. (judo has like 65 throws... but competitors have their own set of 4 or 5 throws that they use for competition. If each judo player only knew 7 or 8 throws... over time, many of those 65 throws would disappear and have to be rediscovered the hard way)
Why does the down block technique and the advancing lunge punch show up so many times in the kata / forms? Why would a catalog list the same item like 30 times? It showing that these particular two sets of techniques (remember the ven diagrams for each) have many ways to transition into and many options to go to after. Looking at the kata / forms this way... the combinations of things that you are practicing get very big very quickly. Once you find that this move is not only a punch and a block, but also a lock... you just found a ton more combinations you can use... and you have already been practicing the most important 80% of the new thing you just found.
Anyway, thats just how I look at it.
Assume each technique (punch, block, push, throw, lock...) is a circle. Now, you are going to make a ven diagram with a bunch of those circles. If you pick the right punch, block, push, parry, throw and lock circles... your ven diagram will have something like 80% of the area shared between the circles you chose. (if you pick the wrong circles, you can get very little area shared)
So, if you get two ven diagrams, each consisting of their own sets of technique circles, such that each diagram has 80% or more shared area... then if you practiced one technique from the first and transitioned to one technique from the second... its like you are practicing all of the first set of techniques together, and then transitioning to all of the techniques in the second set. So then, in application, you could pick any of the first set and then go into any of the second set.
You do have to remember, that only about 80% is shared. The other 20% needs to be practiced. Which could be why this one is a "block" and this one is a "punch." That way you are also getting your block, punch, parry.... practice in as well.
Additionally, the 80% of shared area for the set of techniques, is not a random 80%, but rather the most important 80%. The 20% that you have to change, to change a block into a punch, is the least important 20% of the technique. Yes, I realize that your fist has to take a slightly different path and strikes with a slightly different surface when blocking verses striking. But, if you have not developed the power, the speed, the structure, the connection to the ground... then shape of your fist is not really that important... as there is no power to deliver anyway.
So if you think of the form or kata as how to move from this set of techniques to the next set to the next set... now, there is a ton of stuff to look at.
Now, if I wanted to just practice the techniques and "shadow box" with them or drill with them... that works too. But, if you are trying to pass on all the things you learned to a large group of people, who will be instructors of many more people... you will notice that different people like different combinations. Each of your instructors will teach their favorites and each student will concentrate on their favorites. By making people do set forms or kata, you maintain all the patterns and combinations. Those things remain for future students to rediscover. When they do rediscover it... they already know how it fits into everything else. (judo has like 65 throws... but competitors have their own set of 4 or 5 throws that they use for competition. If each judo player only knew 7 or 8 throws... over time, many of those 65 throws would disappear and have to be rediscovered the hard way)
Why does the down block technique and the advancing lunge punch show up so many times in the kata / forms? Why would a catalog list the same item like 30 times? It showing that these particular two sets of techniques (remember the ven diagrams for each) have many ways to transition into and many options to go to after. Looking at the kata / forms this way... the combinations of things that you are practicing get very big very quickly. Once you find that this move is not only a punch and a block, but also a lock... you just found a ton more combinations you can use... and you have already been practicing the most important 80% of the new thing you just found.
Anyway, thats just how I look at it.