Real tricky, and a lot depends on just how you plan to use the RV. I grew up in a family that had eight children, 5-6 of them at home most ot the time (we were spread out over 18 years). 60s, RV was going to be towed by a sedan or station wagon.
We started out with a "16 foot" TT (would be called 20 today) with a sleeping overhang over the tongue, and pipe bunks. We could sleep 10, seat 4 to 8, dine 4. Two in double bed in overhang, grandma and grandpa in the tiny bunk of converted dinette, two teens in pipe bunks at the back the four youngest bundled into an almost king size gaucho in the back. While travelling, a couple of us slept in the back of the station wagon to make more sleeping room available in the TT, and at destination grandma and grandpa stayed with Mame and Gilbert in their no utilities log cabin. There was so much sleeping room in the TT because there were not the kitchen and bath facilities expected today. This worked for travelling, not for camping. When we ate, we ate outside.
When the family shrunk down to mom, dad, youngest son (teen) and three girls, the family switched to a popup camper. The purpose of that was camping, not rolling motel. Big bunks at both ends took care of sleeping parents and girls, dinette or "sofa" bunked the boy. The nicething about popups is the expansion from a small box to a large family camping space. But a popup is not a house on wheels.
I think today's hybrids are a nice compromise for large families not prepared to haul around a 32-40 foot house trailer. I would look for bunks in the tent expansions at both ends, and coversion of both dining and seating (jackknife or gaucho) space to additional bunks. The crucial thing becomes "who can sleep together." In my era of 3-4 children to a room, packing that many into large shared beds was not a big deal, made for the camping adventure. But if coming from a culture of one child per room, the expectations could be one child per bed, and that can be hard to satisfy with what a van might tow, even if the limit is 10,000 pounds.
I suggest you go to RV shows, look at large popups (some have two dining areas), 20-25 foot hybrids, and the largest bunkhouse ultralights the dealers might bring. You may be choosing between the three categories, or among the options in one of them.
