Consider walking around the resort with little legs, unless you'd just take a stroller everywhere. Saratoga and OKW in particular can be more walking to quick service, nicer pools, etc. AKL to a lesser extent. Boardwalk can be a longer walk way in the back but I would rule it oit, id just request closr to lobby. Poly, VGF, BC, and WL are all alright. I think the compactness of BLT and Riviera are underestimated benefits, and I'd give the edge to Riviera because BLT requires visiting the main contemporary building for more dining, buses, etc. At Riviera, Mom/dad wants to run down to grab a drink, mug refill, or ready mobile order? Back in less than 5 minutes. My kids loved the Riviera splash pad and older one loved the main slide by age 5. Toddlers are also loved the skyliner. My kids also enjoyed taking the skyliner to Art of Animation and just walking around the resort.
ETA: You mentioned resort stay so I'd also consider resorts with activity centers (I forget the name). There are good ones at BLT, Jambo, and Kidani. BW and OKW have them but they're not as nice, imo. Riviera I believe has a makeshift one with most of the same activities, I just don't think it was intentionally designed and carved out as dedicated space.