ZK is less set in stone than other RTS. It's difficult to assume the specifics. Where other games have build-orders down to the second, set factions and precise building placement, ZK is loose and requires constantly updating your approach to available information. Where other RTS converges on compositions of 2-4 units, ZK begins with mostly monospam but as economies scale the compositions go truly nuts (watch any


fahx vs.


Stuart98 endgame for examples). Planning is therefore very different to other RTS.
I would describe my approach as:
Knowing the loose parameters that predict which army wins. These are fairly simple for 90% of cases, involving unit match-up, reclaim position, and relative army size. Most of the complexity comes down to unit match-up, but there are simple rules that will ease the cognitive burden of this substantially (e.g. the skirm with more range wins). The only time an exchange should be decisively won is if someone has a diving force so strong they can win against a retreating or entrenched force. The windows for decisive victories are therefore not that common outside of opponent's mistakes. The default move is not to take commital fights unless you see these windows, which is not something easily planned around.
If you are not going to win the fight, don't take it. If you're going to lose the fight you need to figure out how to get the time to switch to something that wins the fight. If it's in your fac and within your budget, you're fine. If it's in another fac, you'll likely need to concede some territory to get there because now not only does their army beat yours, but yours is now 800m smaller. What you switch to should be a strong counter to make up for this. So most planning happens as a way of not losing a fight, not of winning it.
If you are winning the fight, you either want to leverage that advantage while they switch (e.g. take fights or territory), or if you're confident in their next move, adjust your composition to maintain your advantage post-switch.
So for me at least the plans come from either switching out of a losing match up, or they're built-in to the match up and so feel more like a flowchart? It's not that there isn't planning per se, but my brain is too smol to do sophisticated planning while also adapting to the context of the game.