The shells are probably fine, the bodies have been eaten, the puffers sucked them out. They may be too small to crush at this point. You can always hide food in the shells to give the puffers incentive to go shell crushing.
The rams may have been too big and they couldn’t figure them out.
It’s probably for the best the assassin snails were killed and aren’t with the rams. They get their name for killing other snails, which would destroy your ram population.
My puffers look like they ate a marble after eating, and are similarly sized to yours. They are fine. Puffers naturally expand after feeding. Without scales and having expandable bodies, it shows very well on them. It will go down soon.