I've never had a problem getting a group of chairs for my family, either at the Beach pool or the Courtyard pool. But... I don't usually travel from June-Sept. I like the Courtyard pool which is the "quiet" pool. It's big and roomy, really pretty. Zero entry and a hot tub. I can't imagine it ever running out of chairs, honestly. Courtyard pool bar has drinks and a few food items. The rest of my family prefer the Beach pool, which is much more "happening" with the kids games, louder music and the slide. The Beaches Pool Bar & Grill menu is larger and more varied, by far. I could see it being difficult to find a bunch of chairs together there, especially in the hotter months, but like I said, I've never had a problem getting chairs at either pool.
I had a group of 10+ with some little kids one time, and I rented a poolside patio at the Splash Pad (which is next to the Beach pool). We had a pool day planned. Everyone was coming and going that day, and it was nice to have a central location w/drinks and snacks and a dedicated member of the pool wait staff. The moms/young kids hung out at the poolside patio and splash pad while the kids/teens hung out at the Beach pool and occasionally came over for a break and to check in. I found it convenient and at the time, the price wasn't overly horrible, but it wasn't really necessary. There were plenty of chairs at the Splash Pad for the moms w/young kids and the kids/teens had zero interest in being anywhere other than the Beach pool. I don't think it's something I'd ever do again.