Bear in mind that G1 Sludge doesn't combine. And as a "Scramble" gestalt style limb robot, it means that Sludge has to have four modes. We know that HasTak did consider making a dinosaur gestalt team and got as far as creating concept design sketches for it. The engineering would be similar to the G1 Terrorcons and the aesthetics may have been similar to Pretender Grimlock. Basically, they would not have looked like the Diaclone-based Dinobots that we all know and love.
I think the fact that the POTP Dinobots look so similar to the G1 Dinobots is already pretty damn impressive considering that they are burdened with the gimmick of being able to combine. And for the most part, I think that the gimmick is relatively not too intrusive. So would the POTP Dinobots be better if they didn't have to combine? Probably. But I don't think that they're terrible. I have no desire to combine my POTP Dinobots but the fairly minor compromises made to accommodate their combining gimmick isn't a deal breaker for me. I've seen Volcanicus IRL... my eyes glazed over from the lack of interest.
