defMON uses CIA timing. The "ticks" that were mentioned here doesn't relate to that, though. That just means the number of times the player code needs to be called to advance one step in the sequence.
So.. there are two factors involved in "speed".
1. The number of player code calls before advancing one step further in the sequence. In defMON the "speed" column in the sequence specifies the number of ticks until next step in the sequence, BUT... it is somewhat non-intuitive. (There is a reason for it actually, but..) Writing "2" in the speed column actually results in 3 ticks per step. Writing "3" results in 4, and so forth. So the actual number of ticks is always one more (+1) than what is written in the speed column.
2. The time between each call to the player code. This can be controlled with VBLANK interrupt (on C64 it would be called a raster interrupt) or with a CIA timer. CIA timers are much more fine-grained, just like you say.