I live the are build in T1 and heavy sapper have moving penalty both changes are a huge buff to them.
apart from the moving speed debuff, all other stat is the same, meaning the EHP and dmg output is the same, and in live they dont create any issues/complain about combat performance with 3 lmg setup.
The upgrade at 60 mu for repair speed, weapons and armor is one of the cheapest upgrade in game.
The repair is on par with other engie, and the combat performance of it ALONE is nothing special.
Comet/Churchill are separate issues.
the tech path to get to heavy engineer is related.
In the preview there are no real drawback in getting the upgrade and still remain a badly desing upgrade.
The unit perform above it cost and role with heavy Sapper upgrade alone, it does need any other weapons upgrades, that 3 weapons option is simply the icing on the cake.
and what exactly match up that a heavy sapper with an vicker K alone can stand up for ?
The upgrade alone provide a solid combo, but doesnt dis out any thing special COMBAT-WISE (as you mostly concern about their combat capable), and if more weapon upgrads are stacked up, the cost kick in and is a drawback.
i will make it clear, being badly designed and being broken/OP are two difference thing that you are trying to mix up when picking up my line and assuming that we share opinion. And, you are deflecting away from the part that you have to provide your replay on testing that prove the OP in heavy sapper 3 lmgs combat performance.