Below is the second-by-second breakdown of the run. The excess time is for the unskippable dialogue. You want to ensure you do not get housed to avoid additional unskippable dialogue. You should hover over the initial barracks location to place, then queue a vil.

For this run, I re-bound the select all barracks hotkey to shift+b so I could hold shift + press delete -> b -> q in order to queue in all barracks without getting housed as quickly as possible.

Notable points are:

11 & 12: sending two vils to work on the new barracks. I also shift-queue the remaining vils to the new barracks around here

34: trying to kill the 5th vil as late as possible, but without any delay on queuing the militia

35: I shift-queue the militia to ensure the second is placed, but you don't need to obviously.

55: the del->b->q banana needs to happen quickly. One barracks might be built before the other, but that doesn't matter because the timing of the last militia is the only thing that matters. If done correctly, the last two barracks should be in sync up with the first one.

In theory, this could be 1m30 based on my spreadsheet, but not by my hands. If I divided up the seconds, maybe there's even more juice to squeeze, but I can't confirm.