I support a Hail Mary but if I have to pick a side and I stress I don't want to. I would choice traverse city here's why
the most important lesson I learned in the Erie Campaign is how hard it is to reach out and touch the enemy "war is simple but simple is hard"
the Michigan soviet republic is closer to our supply line and we can easier bring down our full might shock and awe we cant do that on traverse city
edit amphibious operation can be costly as lementon showed us
edit2 Michigan Soviet republic has been described as Stalinists so chances are higher we are going to have to fight them in the future then traverse city whos actually trying to get on our good side
I can't guarantee it, but I strongly suspect that the MSR would make concessions to practicality to have us on-side, probably as much so as Traverse City would.
As for the rest:
At Leamington, Victoria sent troops unprepared directly into entrenched defenders liberally supplied with machine guns and artillery, while an enemy naval squadron circled around behind them and the enemy made a desperate all-in effort to cancel out their sabotaged air superiority
We need do no such thing.
We don't actually have to stage an amphibious landing in the normal sense to hit Traverse City; we just have to march our troops about... well, we'd be basing out of the MSR's territory since they'd be friendlies. Something like 150 miles, I think, overland. That's not
nothing, but... Note the key differences here between the examples you are presenting of what Victoria did, and what we're doing.
Our army has
Professionals Study Logistics. Victoria's does not. Note that
we were able to manage an overland march along the north shore of Lake Erie during the Buffalo Campaign, at a greater distance than we'd have to go to reach Traverse City overland. Victoria failed to do anything to supply its operations overland at any time during the Detroit Campaign. Indeed, they failed
disastrously to resupply the eastern force while operating over the same terrain bare months earlier, going the other direction, and had to be bailed out by vassals! But then Victoria, famously and adamantly, has
No Logistics.
Furthermore, unless Traverse City is a second Toledo, which
I highly doubt... we will assuredly be dealing with much weaker opposition on their end. Even in relative terms, they are unlikely to enjoy meaningful advantages, especially after we finish our current training program.