That's exactly why going first is my number one doom spend. If I don't go first the NPCs get halved in the first round.
That's tough. Luckily my PCs tend to roll complications with bought d20 and are avid reactionists, parrying and riposting quite often. Maybe introduce NPCs with their own doom pool.
But I also ran dry of doom on some occasions. Still, if Not for going first what do you use doom for? Because dealing them a wound early on should make them more prone to buy d20s. Or MaYbe breaking guard as a doom spend is a possibilty.