Haven’t really thought much about it as most of the soldiers including me have used almost solely soldier2 up until the patch, thus focusing on the balance of concussion nades, but after playing some hours today it seems to me that flash nades suffer from the same imbalance.
Just go on an empty server and look at how huge the range is, you can stand so far away and still get almost full flashed, which really shouldn’t be possible. It’s not tactical how it is now, it’s more like a portable minisun, and you can cover almost any area in the game with at least half flash at the moment. Also, turning around and not facing the flash doesn’t do much at all, which means you can get fully flashed from nades 5-10 metres behind you 
I still am of the opinion that Soldiers only should have one tactical nade though, even if you nerf both concussion and flash nades.
