Yep versatile for compensated retirement of Ocean but less specialized CV it is the problem... planned for host 500 troops, Ocean 800 so necessary 2 Bulwark in service, now 1 in reserve, not ready.
A full RM Cdo i have 700 Troops ofc can be hosted sure by Ocean, Albion can in surge, 705 Troops, maybe QE also in surge capacity for some days max about a week before landing operations not long deployment with troops aboard.
In surge an AA Ships can in average host about 1/3 of troops in more than normaly, surely a San Antonio can host up to 1000 troops.
As the Falklands War and other later operations proved, when deploying in combat the peacetime rules for how many troops can be embarked aboard any given ship go out the window. I have no doubt the QECs can carry as many troops as Ocean can and probably more.
Charles De Gaulle can hosted up to 1500 troops but as for QE without or almost aircrafts.
Clemenceau was used in 08/1991 for transport helos and some troops in the Gulf, in an LHD configuration a second possible configuration not improvised.
When i say, i have read 500 troops for QE i mean with an inferior but decent CAW saying 20 - 30 aircrafts after with a small CAW as you say make sense at less as the Ocean 800 or 1000+ troops.