Can we use the Argo SRV to load the Kraken up with a bunch of tanks and basically make a giant broadside machine?

Theoretically, yes. There would be nothing in the game design to strictly stop that. It's moving physicalized objects around. I'm sure there'll be some enterprising people with the Kraken in canyons driving tanks off the cliff edges into it. I've seen people do that already on Daymar, just driving Cyclones off hills into the back of Valkyries.