Simultaneously (as in - in real time); each player plays their actions. These are either: Placing a token on a space, or removing a token from a space. (Only touch one token at a time, complete an action before starting a new one) Placing usually has requirements and costs. Removing usually has a benefit (gaining resource and or points).
If two people want to grab the same place; higher value token wins; lower scoring player breaks ties. Yes; it's intentional that it will take longer to resolve a conflict than just giving up and doing something else then coming back.
I'm envisaging something like - Spot 1: No requirement, on remove put bonus on spot3. Can only remove if you don't own spot2. Spot 2: Own spot 1, or pay 1 pink thingy (gained from a completely different part of the board). Can only remove if spot3 not occupied. Spot 3: Own spot 2, on remove gain all the bonuses on spot3.
So one player can intefere with another; by snagging spot2; but then someone else can just hold spot1 to stop them powering it up and getting much advantage.
Total actions in a round is limited, somehow - probably some resource is a net negative and you'll run out.