Just think of it as a platform. Say you nailed together a square using 2X4s. The you put 2X4 studs/ joists between. Layed on the ground it is solid. Because it all rests on the ground. Without the studs, if you stood on one 2X4 it may start to roll over. With enough weight.Yes.
I could probably get rid of the outside 2x8. The 2 boards running vertical on either side of the sump are joints.
I just try to think about this stuff as simple as possible. Sort of "what could go wrong".

