Does Confront work after units are played

No — Confront only affects units you play after it resolves. It reads "Units you play this turn enter ready," so it does nothing to units already on the board, exhausted or otherwise.

So you can't use it to ready a unit you played earlier, and you can't use it to un-exhaust a unit you just exhausted for a Standard Move. Play Confront first, then play your units — those enter ready (FAQ #7621, Rule 144.2).