snakes up smash is pretty much only used for edgeguarding so they can shut down our options or as an approach. grenades are used at distanes and for switching direction in the air, but are only a threat from a distance.
when hes throwing grenades at u just keep camping him but be on ur guard. f smash is not an option if a grenade is in front of u cuz itll blow it up, so if snake approaches then grab will probably be ur best option most of the time
if he is cooking them, hes probably pulling the bomb, shielding,(hitting pikmin off of himself?,)and then throwing the grenade so it blows up once in reach of you
off of the top of my head the best thing to do is just predict these cooked grenades. if he pulls one and drops it, be ready to shield or dodge an explosion 2 to 3 seconds later
f smash beats dacuz unless grenades are near us. if they dacus with a grenade in front of u then a pivot grab,grab, or fair seems best. when theyre using charged upsmashes for edgeguarindg u really just have to play smart . i wouldnt try getting back on stage when there are upsmash missle things falling downward.