Sorry this is a weird question but what is the fur on the hind legs/rump supposed to feel like?
The fur on Orion's neck shoulders and sides is quite soft (not like his baby coat was though) and if I run my hand backwards against his coat each hair separates nicely. However when I get to his rear legs the undercoat is much much denser and it does not separate like the rest of his coat, it is really quite solid. I can still part it and see the skin so I don't think it's matted as such but I don't know if the denser almost carpety texture is normal? I groom him 2-3 time a week, do you think I need to be doing it more often?

Mishka's fur in that area is the same. It always looks nappy too but it seems to kind of "clump" even though it's not actually.

Same with Juneau. She has a snapped tail, so the base of her tail clumps up as well. I've tried brushing it but it just goes back to normal in a few hours.

Karma and Kato both have that too...It's normal considering that's where they sit. The fur back there will always be nappy.