Adjusting the tiller will have an effect on the timing of the c.5 cams it will effect the sync. The sync can be tweaked by adjusting the tiller, but the best way is to either twist the control cable or the buss. Which ever you do to one you'll need to do the opposite to the other.
You need to sync the cams first before attempting to time the cams.
Basically put, the sync is ensuring you have equadistance between the limb pockets and string for both upper and lower limbs. Once that is achieved you can proceed to timing the cams.