I have no experience in grappling etc... what I do have is a lot of experience in construction and I will say that with certain things it's not always about how strong you are... you need to know how to lift what you are lifting.

This is why I don't think you should be too concerned about what you need to individually develop... a lift like that is a compound movement so that's how you should train.

Over at www.rossboxing.com they're are loads of good compound exercises involving sand bags... exercise balls filled with water... all sorts of crazy stuff...

Look into it.