Most Doldren players play him foolishly and go astral form in a spot that is too close. You have to take the time to run ALL THE WAY to the farthest point on the map. That way you are too far and removed for a sniper, even Harec, to reach unless he goes into enemy territory, and if they really want to seek you out and kill your body, fine, then your allies can focus on the objective while the antag is taking a jog to the edge of the map (depends on the map). Most of my mistakes as Doldren verses the antag is not being patient enough and waiting for my allies when I didn't have to. I tries to solo too much, and that's not great unless you are stalking a sniper antag, they only have 60 health and that two hits or one head shot. But other antags, like fricken Hanz, you have to be patient.
I remember that match and it was NERVE WRECKING! I wasn't all, "Yay! We won!" at the end, I was like, "S***, I need to log off." PvP isn't for everyone, even if you win. I don't even like Doldren, I just use him because I'm sick of antagonists. And on certain maps, and if you play conservative and VERY difficult and don't get too excited (like I did), you can at least win the match.
I really feel bad for alien snipers though, they REALLY can't do anything against him. I felt HORRIBLE after dominating a really high level Harec Antag, and it was just me the WHOLE match. I focused on hunting him and nothing else. But I also know the gut will destroy us on Short Fused and has before when I DIDN'T play Doldren. That being said, I felt like S*** after the match. But they force this on us, nothing else we can do.