Not sure how I missed this.
So to clarify, are you saying that its not simple because you can't reach the G C F Ab all together as a unit cleanly?
if you rotate to the chord from the G (feeling beats as written) the chord is probably going to be a mess.. middle notes will be uneven..
has to be grouped chord first? so bounce the chord, C F Ab, omit the G from the equation. Get it going consistently at the rate of the tremolo, as if its on the beat rather than off the beat.
then add a note with the 5th finger, B. Still work as a whole chord, then make that a tremolo, but with the chord on the beat still, somewhat like an inversion of the first bar.. once that's comfortable increase the width of the leap between chord and 5th finger until its down to the G.. this whole bit should still feel like working as a single chord, not a tremolo.. chord first, 5th finger trails behind.. rather than an individual strike
(whole process takes only a short amount of time)
..then put the beat back as written, but still perceive the physical as a chord first, 5th finger second arrangement.. in groups of 2 notes.. so mentally its kind of an offbeat syncopation.. at least until it settles in and you don't have to think about it.
...use brain.. report findings.
alternatively, tell me to shut up because you've already done this kind of experiment... I'll probably try it myself in a little while to check the validity of my comments as a learning tool in this exact situation.