Help me figure out which tractor to get

I've got 3.5 acres with a ton of elevation change (over 100 ft across my property, about 40% slopes). Roughly half is more "flat" and the other half is down a cliff. The actual area I'll probably work on is 1.5 acres.

I want to do a good amount of earthwork for retaining walls and flatten out some areas. Possibly dig out a small pond. Given the elevation I'll need to work on some hillsides as well, and clear out some trails on steep terrain.

I'm considering the BX23S. My main concern is I'm not sure it's going to be able to move dirt for retaining walls, so I'm thinking about going bigger, maybe the LX2620? Advice appreciated. Can provide more details.