Hey Spray,
I would say you could learn the rollover and shoot it until you can hit either "post" consistently, with or without looking. You'd have to have a good table at home or at your friend's to get to this quickly enough, be able to experiment with different wrist and shooting styles.
Using the pull shot while you're learning your new rollover, you can start using your snake more and more. After enough practice and "live" use in your locals, you should get to a point where you know which shot, the pull or the snake, is stronger that night. Or you could even switch between the two to keep the defenders guessing, during the match, during a game, even during each point.
Having both shots is like pitching in baseball, the more solid pitches you have, the deadlier you are. And you may have your "money" pitch, but you can't just keep using that, no matter how consistent you are, because you're gonna get tagged. Having 2 or more "money" pitches is exactly that, "mo' money." I'm sure you've come up against one or more "unconscious" goalkeepers in foos play, in local DYPs, as well as regional and national events. No matter how well you're executing, these defenders just brick you.
Those multiple Cy Young hurlers like Pedro or Rocket or Maddux etc.,, all have that monster pitch like a hard-dropping fastball or an extremely nasty slider, but they also have 2 or 3 others only slightly less scary, but just as consistent. I've noticed early on that the "mano a mano" pitcher vs batter confrontation is the closest thing to the set pull, kick, or rollover shot on a defender.
Switching to the other shot, which by then you've also practiced a lot and won't just screw up at meatball or meatgame, gives you the extra weapon or weapons. I've seen too many goalkeepers just completely limit or shut down someone's vaunted rollover, or pull, or pullkick or pushkick. At least for that game or that night. Nice to just line up and crush goals with your main or favorite shot, but up against an unconscious goalkeeper, each additional block just burns you up more, wrecks your concentration for the whole game, and pumps the opponents up even more.
Foosball's always been a game of adjustments, since you can't take a 20 minute timeout, go home, and practice whatever seems to be out of whack. I believe this is also why you see so many forwards, after losing a match, take the remaining balls and shoot their main shot with so much anger, trying to figure out why they got bricked. More shots equals more weapons equals more wins, and more peace of mind.
And the more shots you have, the more shots you get a "feel" for when defending them, because (hopefully) you can see which holes that you yourself look for when shooting, are open or not. That's why you should never give up any decent pull or push/pullkick or backpin, which is a lot less familiar to pure rollover shooters that never shot them well, or ever.