It definitely is a far stronger combo in onsal than in the other FL maps for obvious reasons. Is it too powerful however? Difficult to say. In a chaotic situation I think doing the cover capture is easier than the counterplay. I dont think having a buddy you queue up with and have on VC is that big of a hurdle. I assume tons of people queue up in groups of two or three. The strength of this combo does not lie in having two people walk up to a point where an entire enemy team stands. If the paladin combo manages to capture such a point the team guarding the point messed up majorly. The strength of this combo is when it's a symmetric teamfight right on top of a point. Then targeting the paladin is very difficult in my experience.

I havent played a lot of frontline but whenever I got onsal the team that won was also the one that managed to move as a group and won the fights.