Starting simple gives you more expressive headroom.

Locking in does not imply bass and drums are playing the same notes.  Each could be off in their own world and still be locked in because everyone has the tempo nailed, as well as the 10,000foot view of the song structure, i.e. verse->chorus->etc->bridge. 

All members transitioning song sections, together, in a manner that supports the music is what locking in is all about.

An experienced bass player will have their high and mid frequencies dropped out of the mix so as to eliminate muddiness or stomping on other instruments frequency envelope.  I say experienced vs. good because there are killer bass players that do not have an understanding of frequency and how instruments interplay.  This does not make a poor bass player, but rather just some person who does not have experience in this area.  Understanding each instrument - in your bands - frequency envelope and adjusting your instrument around this is the first step in making the band sound clean.  Forgive me if I'm stating the obvious.

You could get together with your worship leader and bass player and suggest they work as a team.
Why not seek to improve, rather than living with the status quo?