Total Mayhem takes Total Annihilation, bugfixes and extends it the way Cavedog might have. Early game pace is quicker, many new units added (longtime players may recognise some 3rd-party units), including a whole new 3rd tech level tier. Existing and added units have been bugfixed, rebalanced, re-modeled, re-textured and re-rendered to equal or exceed the standard of the original TA units.
A demo (animated gif) of the Zephyr's shield in action. The Zephyr's shield absorbs 67% of damage! But if it takes more than 12 hits in 12 seconds the shield is depleted and the unit takes full damage thereafter.
Uh, I'd change that to about 5 hits in 10 seconds. 1 hit/s, even for Total Annihilation, is a bit much.
I also think you should change it from 67% to 50%.
Can you back up these suggestions with some reasoning please.
Are you familiar with Total Annihilation - or indeed with the Total Mayhem mod? There are a lot of rapid-fire weapons that will quickly overwhelm this unit and kill it.
Arm are heavy on rapid fire, and RF units and turrets add a lot to TA, they are the main DPS on the Tech Trees. These are why this game is completly balanced and modern, even by todays standards.