My little nephew loves the Sigma Six guys I got him. I basically bought an entire collection loose and complete. Close to maybe 100 figures total. Didn't pay much to be honest, the guy seemed like he really wanted them gone for space. I'd wager they are about 1/9th. The mix of cloth in the line raised some interesting questions about having the choice to use cloth or plastic in some cases. These were super durable.
Hell, I loved this line too. Just sorting them for my nephew was an interesting experience. The design and modularity was super creative. The added size also allowed more detail.
The potential is there, the big question though is always how much "support" a new scale would get from the entire hobby.
I remember getting some beat up like 5th hand Micronauts as a kid. I thought they were pretty awesome, but vintage Star Wars basically reshifted the entire toy industry and while Micronauts were cool, it's not like, AFAIK, there wasn't much support around the scale.
I hate to say this, but the Mego body type is a classic for a reason. Extremely robust. I had mostly LionRock knockoffs of Megos, but I'm not seeing why to reinvent the wheel here. If it's going to be standard human figures, we wouldn't see the bodies underneath the clothes and gear most of the time anyway. I'd say for production cost savings, just reboot the core Mego body type with some improvements.