Well I've only really played naval battles a bit after live & more recently in my Odrysian campaign.
I think original balance is well known with transports being grossly OP.

The recent battles I found my Medium Raiders were easily able to defeat enemy transports by ramming, generally 2 rams to sink from Mediums, sometimes only 1.
Heavy Raiders easy do a 1 ram kill & have Thracian Nobles on the off chance of getting boarded.
Most of my battles were not much more than frontal ramfests with generally massive enemy losses & minimal friendly losses unless I was significantly outnumbered.

Combat has been horrifically fast -> I have played most of those battles on slo-mo with occasional pauses to check situation & deliver orders.

I believe new combat has much slower ship movement so I may be able to actually use normal speed.