I would take it a step further, and stop thinking of the arts as being different. It's hard to put in words exactly what I mean. I think if you imagine your style as a tool box, and your techniques as tools, you'll be close to the mark.
So as a new student, you are unsure of what all these tools do and how to use them. As you get more experience, you will come to understand that you don't need some of the tools you have, you will never use some of the tools you have, and some of the tools you have aren't working properly. This is when you should start looking around to see how you can supplement your learning, to see how you can get some more, or better, tools.
So rather than thinking of yourself of as X type of martial artist, with elements from Y, I believe it is healthier for someone just to think of themselves as a martial artist (or fighter, whatever term they want to use), and to use whatever works for them.
I hear what you're saying, Adept, and agree, to the extent that we're talking about
tactics. A good throwing technique that lets me set up a shot to the attacker's throat or temple is going to be of interest to me no matter where it comes from.
The problem I see arising comes when you try to reconcile very different
strategies. This isn't my distinction, it's one that's made in Kane and Wilder's great book
The Way of Kata, and their point is that what gives a particular martial art its distinctive character is the overall perspective on how to conduct the fight, not necessarily the moves involved. There was an interesting thread---maybe still going on, I think it is---`when your cup is too full', or something very close, was/is the name---where the original poster expressed surprise that an Aikido teacher, demonstrating a takedown move to someone, didn't supply a finishing move as followup, and when she asked him what it would be, he responded `That's
it'. A couple of Aikidokas following the thread noted that, from the point of view of Aikido, the takedown could well be regarded as the finish---it was a move such that a bit more application of force in the right way would result in a broken wrist or arm, but unless there were actual reason to supply that extra force, the takedown indeed ended the fight, form the Aikido perspective.
In TKD a takedown isn't usually regarded as a finish; a throw isn't an end in itself, and so on---the more general idea is that they bring vulnerable points on the attacker's body into range of a severe damaging strike, and
that's what ends the conflict. Sure, there could be exceptions based on opportunity and circumstance, but the general perspective of TKD and other karate-based systems seems to me to be, end the thing right now, with a hard damaging strike. Aikido, karate, TKD and kenpo might all use the same locking/throwing move, but they have different strategic ideas about how to conduct the fight, and the same holds pretty much for any two MAs that are genuinely distinct. Just how distinct depends on how much the strategy differs---between Aikido and Muay Thai, say, it would be quite a bit!
I don't see mixing strategic ideas in the same toolbox, is my take on this. Tactics, fine. But if you try to mix strategic ideas, you'll probably wind up like the proverbial donkey given two pails of food at opposite ends of its stable who starves to death because he can't decide which one to eat from.
IRather than using Toolbox X, with a few tools from Y and Z, just take all the tools you like, and put them in your own individual toolbox.
Again---as long as we're talking tactics and techniques you can adapt to your `home' strategy, no quarrel with with you're saying at all.