Energy to mass

when you don't have air superiority is because you lose that, or you air player is a noob.
also when you build some T-3 AA you aren't Turtling.

Turtle is not a Strategy because you don't do agressive actions, make some PD, or make som AA is, not Turtling
Now only make PD, and/or make only AA is turtle.

just put some like: 1 mex make 6M/S 1MetalMaker make 3M/S and use a lot of power(in SupCom http://faforever.com/faf/unitsDB/unit.php?bp=UEB1103,UEB1104,UEB1101)

I think even the 2nd strategy is valid. All is fair in love and war.
In my eyese, all possible builds are valid in a tournament/ladder.

If you have 20% map control, then turtle down, build turrets, and prevent scouting.
Then nuke rush is a viable option.

You may call it a cheese build, but it really depends on your definition of cheese.
In Starcraft 2, most ladder players will call a zerg rush/bunker rush to be cheese builds.
But you seen the Starcraft pros? That's exactly what they do.

Mass fabs were made pretty redundant in Forged Alliance. You should separate SupCom and Forged Alliance because in SupCom they were better than t2 mexes.
Basically no one makes massfabs in competitive 1v1. They are used sometimes in FFA though. There is some use for mass fabs after all your metal extractors have been upgraded fully but that is very late in the game and is usually better to simply grab more territory.
So whats the point in adding an underpowered metal maker?

like I see a cast from Zaphod where he has only two mexes, so the Metal maker is not to boost your Eco, is to be used as an inferior substitute. of course they don't need to use This lot(1-150) of power, but yet making "expand better than tutle."