yes the advantage for premium players is too big now.
I used to be premium player in my realm and after "inconvenience" with user support from IO i decided not to give them any more hard earn cash.
Given that i play now without credits i must say i develop FASSSST. Credits CANT compensate for lack of fighting. I take all resources i need from others and in less than a week i almost reach 2k points.
So i must disagree with you. At this stage credits make almost no impact if you went warrior way.
By the way, i must say i like what they did in V5. It's much easier to fight and develop. Some things make me crazy every time i use it (like spying and than I CAN'T attack that player from spy report than i have to go to map and . . . . . ALSO like battle simulation. I spy and than i have to memorize army, fort lvl and other things because i can't have spy report and battle simulation open at the same time or in other window)
But overall my humble opinion is that this game is better than V4 - later we would see how much of impact imperian would have with damn strong forts and guardians.