I'll say again, I've not seen much proof of the "you can't feed raw and kibble together" rule and I have at this point known hundreds of raw fed dogs, fed in every way imaginable (all RMBs, prey model, raw and kibble fed together/separately, all ground, with veggies/grains/carbs and without, whole prey, etc, etc).
The gulping issue...it depends on the dog I think. It's rarely an issue but it can be an issue. A friend of mine just had a bad time with her dog having a colon obstruction from chicken necks of all things and that dog has been raw fed from weaning on. Loki eats all RMBs without issue except turkey necks - she will swallow them whole and choke on them. Turkey necks are huge, so the theory of giving bigger stuff to discourage gulping doesn't work with her. I also know another raw fed since weaning dog who had an colon obstruction from a turkey neck. OTOH my GSDs were all gulpers, they never crunched anything more than a couple times and never had any issues at all. However, giving "recreational bones" (large hard beef bones) caused pretty bad wear and breaking with their teeth. As old dogs their teeth were clean but many were worn all the way down to the gums. There is a definite risk with such bones as far as breaking/wearing teeth down.
And as far as dental health goes, IME raw fed dogs pretty much always have better teeth than kibble fed dogs regardless of what sort of raw feeding their owner does. Most dogs are not chewing RMBs enough for the bones to be cleaning their teeth. However, feeding raw food in itself means the dogs tend to have better digestion, are using their molars as they were intended (crunching bones vs. chewing cereal) and not having a big build up of gooey, paste-y wet kibble residue. That said, I do feel dental health is also genetic. Some dogs have weaker/softer teeth, teeth with more shallow roots and/or lack proper enzymes in their saliva and even with the most ideal diet, these dogs may still need some extra help in the dental area, although not usually enough to require a cleaning at the vet's. Jagger gets a lot of RMBs but his upper canines get tartar on them that I have to scale off - the rest of his teeth look great!