In judo, most coaches consider it a necessity to teach and drill combo techniques - stuff like ouchigari-to-taiotoshi. This is standard practice, and you pretty much have to teach combos or your players will think that you are a bad coach, but there is a problem or two with developing an over-emphasis on combinations.
- The harder that you attempt any given technique, the harder it is to flow to the next technique.
- If you don't really try the first technique, then you can more easily flow to the second technique, but you are opening yourself up to some potential problems with feints. Specifically, you have to make the feint realistic enough to trick the receiver, and that can open you up to having the feint countered. If you don't do enough of the feint that you might be countered, then you are not doing enough to affect the receiver, so you might as well not do the feint. In essence, you are training to do half-assed kake on the first throw, which tends to get you countered.
There are some other ideas about how to develop combination techniques, besides "first this then that".
- Either-or combos - you can build combinations by grouping 2-3 techniques that can all be done from about the same position but which throw in different directions. For instance, osotogari and haraigoshi are the same motion and occur from nearly the same place. That means, if you can step to that place that is right between those two throws then you can decide to do either this one or that one. Another good classic either-or pair is osotogari and hizaguruma. Another is kouchigari and ouchigari.
- Chain combos - In this approach, you chain several techniques together and drill stepping from one to the next. This differs from the first-this-then-that combos because you are never attempting (or even feinting) any of the techniques in the chain. What you are doing is doing kuzushi and tsukuri for technique-1, then kuzushi and tsukuri for technique-2 and so on. When you get good at stepping from one place to the next, you can decide at any of them to complete the throw with kake and zanshin. Our favorite chain combo to drill is deashi-osoto-ukigoshi-ouchi-kouchi-taiotoshi.