Well to get Snake you actually HAVE to go missing which can be a downside for some people especially with the pardon cooldown. You also need to have access to the Lab (which most people actually exploit to get into).
I think Snake has more hp/damage than other summons due to the fact that it doesn't have any CC. Literally every other summon other than the Slug (whose purpose is to heal) has CC. Dog has stun, monkey has KB, weasel has KB, hawk has snare/slow, toad has stun, clam has stun, panda has stun.
While the damage it has can be impactful, the CC that some of the other summons have can be much stronger in certain cases so I wouldn't change the snake summon too much.