Good idea.
Airlines should consider offering reductions in their RJ ops in exchange for merger approval and additional slots.
Let's say, remove all of DL's rj's in the NE, Midwest and ATL from service, in exchange for combination with UA, AA or NW.
Same with any LCC consolidation with UA, NW or AA.
I'd say the most effective combinations would be AA/DL or DL/UA, because their hubs are in large markets that SHOULD justify larger aircraft to reduce congestion and reduce unit costs, while still maintain some revenue premium.
US/NW would have a harder time doing that, because their hub markets are smaller.