The lower end freehubs will use only 2 pawl engagement for their freehub bodies. I took apart a Shimano Exage body used for a MTB wheel. I discovered there is a spot for a 3rd pawl, but it wasn't machined and a pawl was left out. The spacing is triangular and equally spaced. So, the 2 pawls that were used, aren't equally spaced apart.

I assume the Ultegra/D-A/Deore XT/XTR freehub bodies have more pawls. Has anyone disassembled one to verify this?

The major difference is the level of finish and quality of the cups and cones in the hubs. Everything else is basically cosmetic and weight shaving. It's only when you reach race spec XTR and D-A hubs where strength to weight performance becomes priority and its cost isn't.

I believe the wheels you're planning to buy will be fine and the 2200 hubs will perform well. I agree with the comments above that you better inspect these wheels and hand true them before use. Also, check the hubs for smoothness, adjust the cones if necessary. I find hubs to be shipped too tight.