For Benihana and Bless7ings, I would suggest a dedicated 2BR (can only be used as a 2BR) at Kidani and, if savanna view, request close to lobby (to avoid very long walks to amenities). It is about 100 sq ft larger than the treehouse, has three bathrooms, king in the main BR, two queens in the second bedroom and a pull-out queen and sleeper (twin size) chair in the living room. It also gives you one long balcony accessible from all three rooms. Every bus has only two resort stops, Kidani and Jambo. If you have a car, you have ideal parking under the building and, with elevators along the two wings, you can park fairly close to your room. There is a Community Hall near the lobby, the pool has a long slide and a kid's water play area (with things for both little and older pre-teen, or even teen, kids). It has its own table service restaurant (Sanaa), and of course you have access to Jambo, with three more restaurants. And you have the animals.
The Treehouse seems small to me for the groups you have. Those bedrooms that each have a queen, are fairly small and the one with bunkbeds quite small. Also, I do not know if anyone is renting a car, but you can only park one near your unit. If not driving, transportation to the parks requires a bus (or walking, which can be long) to the main SSR area and then take the busses that go to and from the parks and make multiple stops within SSR. Though the driving distance to and from the parks, other than AK (8 minutes from AKV) is shorter than AKV, the combination of the time spent getting from the Treehouse to the main SSR busses and to and from the parks will likely be longer than for like park trips to and from AKV.
As to having a car, I personally consider it a necessity for the Treehouse to take to the parks other than possibly MK (which requires parking outside the Ticket and Transportation area and then tasking a boat or monorail to MK). If you have a car at AKV, it can make trips to Epcot and MGM quicker, but not really to MK (because of the need to park and take monorail) or AKV. A car gives you additional freedom such as a fairly easy drive to Downtown Disney or to a nearby grocery store but I don't consider t an actual necessity at AKV.