There are very few players in Ia with all 150 level GBs. LOL
I know not that many in SAJM with all Level150 GBs.
There are very few with L150 at all.
On the US world I play (Parkog) only 57 buildings at or above Lvl 150. Of those buildings 48 are The Arc.
Meaning if they have a Lvl 150 Great Building at all, chances are it’s only a single Great Building: only 9 buildings aren’t the Arc, and those remaining 9 buildings are split between Castel Del Monte, Arctic Oragnery and Chateau Frontenac
The chances of someone coming across a Lvl 150 Great Building at all are relatively slim, particularly if you’re not going out of your way to be in the places those kind of players would frequent. The chances of that Lvl 150+ having any effect on attacking stats is even lower.
Edit: If we were discussing having all Lvl 60-80 Great Buildings, then it’d be a far more realistic concern
Just taking the daily generated Forge Points, (24 Forge Points x 365 Days) would get you a Lvl 45 Zeus utilising 1.9. So it’s not unreasonable for a player to get Lvl 60 on multiple Great Buildings within a year if they’re getting all the Event Buildings and are active within Guild Battlegrounds.