So with these overflow changes, there is now never a chance that GS will use his AOE before Echo uses his grenade and puts Crit immunity on everyone in the attacking padme team, which was one way to make the fight harder and maybe Padme would lose (followed by Echo's 2nd grenade wiping the protection up from Padme's heal skill when she could finally use it)
It's not enough to drop Echo's speed a little to make GS faster than Echo. Because form up gives 30% tm to GS and 60% tm to Echo, Echo will basically always overflow more than GS unless you drop Echo's speed to base (149) which makes him a lot less useful after the start (can't get that 2nd grenade off in time), or you build GS for pure speed (he'd need to outspeed Rex anyway) which would be paper for a tank and would make it easier for the Padme to beat anyway.
So from that perspective, this change really blows. Before it might have been 80% reliable, now it's 100% reliable as a counter.