Not for just 40points (and that's without the other upgrades). I can't find the full doc I wrote, but remember a lot of it, due to the lack of spawnings, they were granted a boost to their total magic item allowance. (This is way back in the 6th ed times when heroes had a 50pt and lords a 100pt limit). Slann generations: I also found my take on Slann spawnings, where I think I fixed the problem of people only taking 4th or 2nd gen slann. It worked in a similar way as the current disciplines: A 3rd gen slann got his + 1 wound, just for being a 3rd gen. A 2nd gen slann got + 2 wounds, just for being a 2nd gen. The disciplines were instead called teachings. Each teaching you brought (maximum of 4) increased the generation level, so a bog standard 5th gen Slann was allowed 1 teaching. Teachings come from different old ones (Tepok, Quetzl, Tlazcotl, etc...) Some teachings could only be taken by 4th, 3rd, or only 2nd gen Slann, but would quickly become costly. Some disciplines became more powerful based on the Slann generation level (So for example, the teaching of a Tepok, quickly becomes much nastier if taken by 2nd gen Slann, rather than a 5th gen). But as a huge FYI, all the abilities were based on the 6th ed book, so an ability to ignore miss-cast table rolls might lose you friends if you were to use it now.
All great ideas! Spawnings and Slann Generations would help give a little variety back to our cold-blooded army it solely is missing. Just to name a few! Have you ever thought about going back and trying to upgrading them to 8th ed? Just incase things don't work out with 9th ed? Or just to try out for fun!
I'd probably have to re-write much of it, as it was all done for 6th ed (when magic phases could be INSANE). I wrote it all for fun in between 6th and 7th ed.
I know it would be a lot of work, but you could make it a community project where we all could give our Old One thoughts on the changes or improvements? If your up to it or have any time for it? The idea of some old to new rules to try out on our enemies sounds fun! LoL