I'm basing this off of the stage descriptions of the previous events:
Most stages have a max time limit; engage all targets within x minutes or DQ/ zero out the stage.
There event score is an equal weight of running and shooting scores.
The shooting score has a ceiling; I.e. there is a 100% score multiple people can obtain.
The running score has no floor. Fastest time sets the 100% mark and everyone is scored relative.
If I or someone else crushes the running we'll have a big advantage. If you shoot 100% I think its likely many other people will as well, and then it comes down to your run time.
There is some downtime before and after stages. When you arrive at a stage they start a timer for your downtime while you get briefed or wait on another shooter. This time is recorded and doesn't count against you. There is time after a stage to debrief, get scored, collect mags, etc. Not a lot of time but enough to shift ammo from a readily accessible pouch on a backpack to a pouch on your belt.