hello and Welcome...
I'm sorry to nitpick this, but DITCH THAT DISH. Those have been known to drown tortoises. Terra cotta saucers are cheap, grippy and way safer!
They can't live together, and in you one pic, it looks like they are. Tort species mixing is a big nono, just because of aggression, and different pathogens, immunities... no
Are they eating a whole head of lettuce? Did they get anything else? Weeds. Flowers?
That coir is too dry. Bump up the humidity to at least 70%, it'll do them some serious good. The pic with light is like 1'' wide for me, so I can;t it properly, but what sort of light is that? I'm only seeing one lamp, and unless that's an MVB, you some UVB pronto! Can they go outside?
I'm sorry, but these things in the pics seem really obvious to me!