Mod/hotkey to select one less unit?

I would love to be able to select one less unit with a hotkey. Would be super useful to micro villagers. For example, you select 5 vills and shift click to build 5 farms. Then task them all to the first farm, select one less unit, task all remaining (4 vills) to the second farm, select one less and task to the third farm, and so on. You can already do this by ctrl clicking one one vill (on the vill or the vill icon in the selection box), but it takes a lot more clicking and you have to be precise Could also be used for a new lumber camp or microing monks (though arguably OP for monk micro).

I don't believe there is a hotkey for this. Is it possible to do a mod for this (that would work for multiplayer)?