Backstabs should apply a slow in PvP imho.
I’ve been playing OR quite a bit (at least, when my ultra low pop server allows me to, since there are over 6 hours long queues), and something I have noticed is just turning your back to the opponent and running away hardly has any counterplay. Even with great axe skills like Reap and Charge, it’s basically impossible to catch someone who just knows how to dodge roll away / lags.
Having backstabs slow players wouldn’t fix people just blinking out of range due to lag, but would still help in the fortuitous occasion an hit does actually connect.
Just my 2 cents.
Of course one could argue “in OR, you gotta fight on the capture point, if your opponent is running away you have already won that fight”. And that’s true. But sometimes I just wanna go for the kill, so that ranged will stop camping me from a mile away, healing himself to full in the process.