We have an advanced setting for this, it's called
CoveFs_WaitForVolumesOnMountMs.
Setting that to a higher value is a better solution than changing the service start up type because that setting takes effect in the kernel. It will actually wait longer for all the disks to arrive before making the pool drive available.
This is not the normally expected behavior in Windows (that is to delay drives from showing up) and the advanced setting is really a kludge to fix this quirk. Normally, delayed starting the service should not be necessary.