At the risk of massive downvote, I’d say it’s totally normal for a Rega xD.
Just kidding ;)
You can lubricate the axle but I suspect the rubber belt to be a bit old and sticky.
Clean all the parts in contact with the belt and try to find a new belt.
There is no definitive answer to your question. It’s all about synergy.
With 2 different amplifiers you could have opposite results.