I can speculate...
Irrigation guys might be thinking one shallow well per Quarter HP. Scratching their heads thinking warrantee and sand clogged valves, clogged sprinkler heads and not enough capacity so they have to add twice as many zones as the contract calls for too. More headache than its worth to them.

Or maybe they just dont do well pumps. Gotta be inspected by plumbing and electical, how are they going to pull permits for it. Plus they might anger some well guy who's brother is the chief building inspector.

Must be a valid reason and the only way to find out is ask why they won't install the well and hook-ups.

I'd call somebody else or maybe just do it myself.

Could also be a case of irrigation contractor not wanting to take responsibility (real or perceived) for viability of wells. Driller could say irrigator hooked up pump wrong, irrigator could say driller didn't install good wells. Classic!
I would also be concerned that the wells have sat unused for 4 months - could possibly have in-filled with chalk or minerals. Best to have driller furnish and install pump.
BK