FYI I did find this
post afterwards with basically the SQL I was looking for to manually inject the spells. I now end up with 1,347 rows in there along with the other table & row counts mentioned earlier. I saw in that thread that 18 tables is the correct number so looks like I might be ok now.
I did play around a bit with melee & bard bots and they seemed to work fine (at level 1 to 4 anyway). So hopefully the casters will be good as well now!