Not sure I understand what you mean.
Force Suppression (Deathmark) - Increases damage of next 10 DoTs by 20%. As such it seems that you get the most from your highest damaging DoTs. Dunno why the fact that one ticks every second and the others tick every 3 seconds matters.
Its not the frequency of the ticks that is important. They are saying the use the Force Suppression stacks for WM/SF ticks instead of MC because they deal more damage.