Guitarplayer196 and Razbo are right on target, as far as my opinion goes.

Prioritize the timing.

In your very focussed practice sessions, focus on fine tuning the choreography of the chord changes - but when playing the piece up to pace, definitely focus on keeping the rhythm going on steadily, even if it's at the expense on the chord being perfect. Try to adjust the chord on the fly, if you can, while keeping the strumming good and steady.

Eventually, with focus and attention, it should all come together and merge into a great sound and great technique.

-Lisa