I've been going through the New Breed by Gary Chester recently, and while some of the systems seem very applicable to grooves that I would play on a gig, others seem less applicable. Obviously this is an excellent book that has received praise from countless drummers, but I guess I just don't see why I should spend time practicing all the systems when I could just focus on perfecting the ones that I feel are applicable to the music I play.
For example, system 2 is sixteenth note groove that you would definitely have to play on a rock/funk/pop gig, but system 20 has the bass drum on all four beats, the hi hat on 2 and 4, and the ride on the ands and you have to play the melody on the floor tom. Personally, I doubt there would be a situation in which I would have to do something like that, so why would I devote my time to it, when I could be practicing something more practical?
New Breed gets the high praise it does, I think, not for its content, but for its
concept. The idea that you should play a repeating thing on some limbs, and then read exercises on other limbs, is very cool. It helps you develop your dexterity and reading chops. But the content gets pretty ridiculous. Half of those systems aren't very realistic. Maybe they seemed so at the time of publication. But the overall idea is good.
I like Time Functioning Patterns, too. Essentially the same concept, the user is instructed to play an ostinato with the right hand, and then play the written kick and snare exercises against it. There's a section for developing interdependence against the jazz ride pattern, too. But, some of the suggested right hand ostinatos are not very practical. I'm probably not going to play "1 e -- a 2 e -- a..." on the hi-hat, with one hand for a whole song. OTOH, I've personally created my own ostinatos, and used the exercises to develop my comfort and coordination, to the point where I can actually use them on a gig.
I also like that TFP presents ALL the permutations that are possible within a given context. New Breed is not that thorough. Although, only NB has reading exercises; TFP expects you to try all the possibilities, and then improv with them to develop your vocabulary.
To your point about practicing something more practical, sometimes it's good to play things that are impractical, in order to develop your coordination purely for its own sake. Having that coordination "headroom" can help the simpler, more practical thing feel more fluid and comfortable. But, playing a line on a floor tom is not much of a challenge; you just move your hand over to the right. So there's not much benefit there, I suppose. Use your judgement when going down the coordination rabbit hole, and make sure it's supporting a bigger goal.