Some advice I've gotten is to play safely and for special before starting a push. Crableg has a lot of room to paint, but it can be easy to get splatted quickly if someone is even just a little bit forward / in an unideal position. I say definitely lean more into running Shot here, because Zooka is really good for entry and for splatting anyone on the grates. Try as much as possible to also pop Cooler before your team pushes in.
For pushes on Clams specifically, It helps to have maybe 1-2 people pushing the grate / bridge that leads to the top right, while the rest of the team pushes onto the ramp. I say position your 52 player top right, since they might have an easier time splitting attention with their wall for defense vs on the ramp where the enemy was probably going to focus their fire anyway. If you're Cooler'd you can also position yourself on Slosher and/or your Range player top right, because the higher ground top right favors both of your weapon ranges a bit more. Or, you could also take the block on the left onto the enemy plat, which is a bit faster and might distract the enemy better if they're defending / spawning in. Your Hedit is probably going to be running a Power Clam(?) so they can position on the ramp while your shot covers them (ideally Zooka first then clearing a path in front of whoever the Clam carrier is)
tl;dr - On Crableg play a bit safer, play for special, and take positions that split the attention on pushes, esp in clams. Hope this helps!