There aren't eight, there are ten. This setting bans demi-gods and gods, essentially, so T9-10 are out. Like I said, it was the old system, but I still use it because it's a little less ambiguous. There's also unpowered, low powered, mid powered, high powered, god tier, with space in between. Point being, T7-T8 is high powered, capable of destroying cities and sponging damage of similar proportion, basically army destroyers. 

To be honest, I've read Alex's sheet, still have no fucking idea what he can actually do. He literally has a power-suit with no mention of its mechanical strength. You ShinRa guys are awfully vague in regards to your power-sets.