He’s right that it doesn’t fit with the combine’s aesthetics. If it were the combine’s black metal, I could see it better. Also doesn’t make much sense having the face exposed, a few quick shots should kill it. Also doesn’t make sense that they’d go through all the effort to make a human tank when the alien synths, human soldiers & vehicles seem far more logical.
They could have moved it to the citadel like they did with the gunship bays. The point is that the enemies themselves weren’t any fun.
The Guard was supposed to fire freely with it’s gun, which is the same as the strider cannon. The strider cannon only fires at & from specified points, so scripted environmental damage can occur, including blowing holes in buildings. It also disintegrated props & kills the player instantly. If you’ve played the leak, you know it just amounts to a strider battle where you aim lower, you have less cove, the enemy is much less likely to hit you & if it does, you don’t get a second chance.
They didn’t have the time to make it fun, so it was cut.