With Marquette being bought out by RA, it made me wonder if the following combination would work as an RA line.
HESR (with CMGN), MMRR, AA. TSBY - This would form a railroad running from Toledo north to Durand, then a split going East to the Tri-Cities and thumb, and northwest to Cadillac and TC.
This combination would allow traffic from all three regions (Tri-Cities, Northern Michigan, Thumb) to be combined onto trains headed south to other interchange partners (IORY, NS, CSX).
From an economics standpoint it would appear to be a smart idea because if those lines merged now you have one railroad invovled from Toledo north instead of 2 or 3. This would seem to open a chance for traffic going to the Tri-Cities and thumb via NS to increase as well since only 2 railroads, not 3 or 4 would be invovled.
The second combo I would look for is the previously mentioned GRE-MMRR (GR-Lowell) and Marquette.
I know all of these would require significant reworking of agreements that are in place, but this is why they are DREAM combos.

