Two MRM-40s would be sweet..
And way too heavy with ammunition. I can see 2x20 MRMs as shoulder mounted weapons(fluff had it that the AC 20 had feeding and reliability problems, which is why the LRM variant became the "best known"). Or even 2x30 MRMs, but only with lots of concessions to weight.
BRB, going to build one to test the hypothesis.
Yeah, just as I thought... 2x30's can work, with CASE, but there's no tonnage for any secondary weapon or speed improvement unless going with an XL engine. 2x40s are straight up impossible at 65 tons 4/6/4(and this is considered slow already)without an XL, and even with one, you'll run into either weight or space constraints before you know it. If you want anything that's still an Axman at 65 tons, that is. For this armament of 2x40 MRMApollo +Hatchet+some X-Pulse, I got down to a 90 tonner going 3/5/3(there's weight left over for one goodie, but no space. And that's with only 12 shots per MRM40 and without CASE. Below that weight or above that speed, the hatchet has to go.
TL;DR version: Won't work, simply not possible. If you want 2x40 MRMs, an XL engine+CASE is out, either one or the other because the MRM40's leave only 3 crits open in the side torsi. And you'll have to shave armor off as well. And only 6 shots per launcher