Is this acceptable for my hermit crabs?

[maroon.ocean]

So I have a large/jumbo hermit crab Julian by himself right now in a 20 gallon long and in a 10 gallon I have 2 tiny crabs Timmy and Tommy. (If you know the reference I applaud you lol) anyways is this acceptable? I remember hearing that crabs can actually thrive by themselves. I just don’t want Timmy or Tommy to be accidentally crushed. Idk if it’s his shell or him or both but Julian is fairly heavy (he’s the size of an orange) and Timmy and Tommy are the sizes of quarters.
I have a empty 40 gallon long should I just take my chances and put them together or no.

[Wai]

They will get along together; in fact the risk of fighting is less with differently sized crabs since they won’t attack each other for shells.

[maroon.ocean]

That makes perfect sense