Techniques are only as good as the fundamental skill of the practitioner. If a martial artist has good fundamental skills, his technique may be effective, if he/she has poor fundamental skills, then even a āgreat techniqueā will be ineffective.
People often misunderstand martial arts training as the learning of techniques, however it is the fundamental skills underlying those techniques that is at the true root of training. These fundamental skills include: timing, alignment, centerline power, focused power, balance, fitness, etc.
As far as the actual strategy of a technique that is effective against a specific attack or situation, that is so hard to say as the variables are infinite including the size, ability, training of the opponent; the situation (sport, drunk uncle, police enforcement, schoolyard fight, self defense). What may be a good technique in one situation would be a poor technique in another situation. It is much easier to define āgood techniquesā in the aspects of sports like MMA, Judo, Boxing, etc, because there are a defined set of rules, desired outcomes, etc.
Even in the sport world, one small rule change can alter the effectiveness of a particular technique. For example the introduction of time limits and judges made many submission techniques much less valuable and striking techniques much more valuable.
In law enforcement and jobs like being a bouncer, there are stand up grappling techniques that are very effective that would never work in mma.
Unless you have a specific scenario that you are training for, the focus of your training should be more on fundamental skills and principles that each technique teaches.