Yep! I completely agree with both people who have responded. Glass surfing = boredom, so caves and other enrichment are needed. The puffers might be scared for a little after adding them, but they should eat soon after.
U would need 35 gal for 2. Bumblebee goby might get eaten if they are small (its like a freak accident tho).
Also, with gobies the tank would need to be even bigger, at least 45 gal