From a monetary perspective, sunk cost to go back to consulting? No way back?

Would it be a sunk cost to go back to consulting right now?

I did 3 years in consulting and now 2 in PE. My fourth year in consulting would have been $250k comp at post-MBA level which I would have done for 2 years instead of ~$300 in PE (~$100k delta). Then I would have gone to business school, so that's a net wash. 

However now that I'm considering going back to consulting - and I would not go back to my old firm because they suck at the industry I like which is stupid long term - I would have to go back to the title that is the equivalent of my 3rd year in consulting (!). My comp would be back down to idk, something below $200k. Whereas MF/UMM PE VP cash comp is $400+ and then carry worth around that (just a data point from my firm).

It almost seems like at the minimum I should do a year of PE, invest as much cash in my future firm's fund as I can and get into the capital call cadence, clip once bonus, then try to leave for the equivalent post-MBA level I would have had at year 4 of consulting anyway! This is insane, no? How do I square this!