admittedly it's complete speculation regarding just how powerful galactus would become after absorbing taa II - as he's never done so on panel. regardless, reed referring to it as one of the most powerful energy sources in the universe, speaks volumes concerning teh powa. imo.
To be honest I thought Tyrant was at 10. I'm not sure how I feel about that.. when they fought Galactus blasts were actually making Tyrant stronger so in theory that could happen again. I've argued for Tyrant on a number of occasions. However, in this situation I feel like the blast(s) Galactus hits Tyrant with would be much much stronger then before and something I'm not sure he could just absorb.