As long as you keep practicing it will eventually become second nature to place your fingers more simultaneously to form chords.

You can help yourself by focusing on chord change motion for part of your practice session.

Form a C major chord. Strum it once. Stop. Form a different chord. G major, whatever you are working on. Strum it once. Stop.

Repeat!

The idea is to focus all of your practice efforts towards forming the chord and getting your fingers in place. Don't worry about strumming in time or anything other than forming the chords.

Hope that helps.