Hmm. Let's talk military (Twilight Valley on the mind).
I think the smaller two footers may be able to serve as drivers or even pilots. But that raises a serious problem: scale. A Compy tanker cannot pilot the same tank as a sickleclaw can. Also, four footers obviously cannot be drivers or pilots so what would they do? Their size makes them vulnerable to weapons fire (granted their immense size protects them from all but cannon caliber shells <20 mm and up>). So would they become mobile radio towers or living armored vehicles?
Also weaponry:
A rifle designed for a Runner like Hyp may be too small in the hands of someone like Ms. Maia. Likewise, Ms. Maia's rifle may be too heavy for Hyp to use.