My experience is that pool players who transition aren't bad potters at all. If you are a really competent pool player, then you'll most likely become decent at snooker rather quickly at least as far as potting is concerned. Of course you'd have to be at a level where your fundamentals are at a certain minimum for that to work. Ok, in the beginning, most if not all potential big runs end unexpectedly from small flaws in fundamentals. It's ok, though, that happens for most new/mid-level snooker players too.
I think the game management overall, not only shot selection, but position, strategy, kicking/safes etc. are all likely to cause problems for people coming from pool. The whole flow of the game is different from pool. The respotting of the colours is especially different, meaning that even though you may be as good as a snooker player at potting randomly located balls, he'll outshoot you on the colours, simply because he's shot them a million times and played position for them from all sorts of angles. That goes for delicate position plays around the black as well, where the big points are scored. Whenever two newer players play each other, that rarely comes into consideration, as the colours typically get knocked off their spots all the time and the game looks 100 times more difficult that in usually is after you learn to avoid bumping the colours as much, and learn the importance of choosing the correct colour to play for etc..
Snooker, as a game, is IMO almost entirely different from pool. Even though I've spent most of my time going back and forth between the games, I always play much, much better when I specialize on one or the other for a long period of time. That goes doubly for snooker, but is also true for pool to an extent. People have wildly unrealistic expectations about going from snooker to pool and then dominating everyone. It's not going to happen, though you may get a boost to your fundamentals that may help your game long term, and pool LOOKS and FEELS easy after snooker, the results will rarely come close to that subjective feeling. Your potting may be great for the first few hours, then you adjust back. Try it, if you don't believe me.