The only pressure to get event units is self imposed, and the game should not manage players time for them if they can't do it themselves. It's repetitive to say, but the one and only solution to running low on resources is simply to stop playing the events. Hell, they don't even need to skip it, just settle for a couple less skill levels or cost reductions.
Resource management is on the player, not the devs, and wanting the game to grind to a halt is selfish as can be.