[...] but as they are using 5e rules and a modern coop focussed engine, there isn't much scope for mechanical similarity, [...]
I'm sorry, this isn't meant as an attack or intended aggressively, but I could not help my derisive sniggering at the juxtaposition of these remarks...
If they can be said to be using the 5e rules, and would still say that about this game, then it goes without any need to demonstrate that they consider themselves to have as much scope to alter the mechanical feel and function in literally whatever way they want, to whatever extreme they feel like without giving up that claim.
