You have to set the initial delay value on one of them (and all the rest of the properties the same). The initial delay value doesn't use seconds though (I guess it uses game tics? not sure, maybe someone can clarify) so you have to set it to something fairly high, like 128. Play with that value until you get the desired effect.
This is a good point. This was probably the concept I couldn't wrap my head around before when I was trying to set these up... If I knew what the conversion rate was to seconds this would be super easy... as it stands now though, they tend to wrap back into themselves so you can never really set a true sequence that loops predictably forever.
We need to figure out what these 'ticks' are equal to in seconds!