The puppy is basically an offensive/reclaim unit. More units like this, particularly a unit that uses reclaimed metal to build a shield or shoots it as projectiles would be interesting. Res should probably have a better implimention too.
If there was any factory that was particularly rubbish at reclaiming (very slow cons, say), an offensive unit that could also reclaim might be called for, but that is a gap that doesnt need filling.
The main reason not to add just a 'reclaim truck' this is that it goes against one of our design goals. We slowed down reclaim speeds a lot quite some time ago, to ensure that you take time to secure wreck fields, that they become a dynamic resource to fight over. This is much better than just ninja'ing reclaim with air constructors.
A part of this was a consequence of greatly increasing the survivability of wrecks, so they arent destroyed as easily- this creates a more interesting and shifting battlefield with obstacles and such, but it also greatly increases the amount of metal available from reclaim (which we also cut). Wrecks can also not be destroyed entirely, debris (25%) is the lowest form, even if you nuke them.