You've got very good players and much better tech. Let's talk about how we can fair up some of these fights.
I take it you're referring to the fight in Koeln, you had 3 hels and a corvo, against 1 jorm 1 scylla and 1 vidar. Given battleships are bad due to the cerb nerf, you took the opprotunity to shoot the battleship while it was alone, and in the process took it down. However, the battleship got a lucky hit on one of the hels that got too close and insta killed it. Leaving just 2 hels and a corvo on 2 caps. In terms of numbers, that fight was completely within your grasp, the issue at hand is more of a matter of coordination, I don't think RHA is to blame here.
1 cruiser was isolated alone, while the other 2 crusiers and the corvo played it smart, running to each other for cover while shooting the BS down, if all the cruisers had played like this, you'd have won.
In any case, hope this answers the question, the scylla is a great ship, but by no means what made the difference between victory and failure.