I don't know if it's a matter of too many voices per say, as much as it is a matter of too many hp taken up with voices. Here are a couple things to consider:
-- Do you need the Nerdseq expanders? This is still a fairly small system, and I find it a little unlikely that you'll need so many extra triggers and CV outs.
-- Shakespeare
You are right. I forgot to mention that I would pair this with the semi-failed rackbrute setup I have which has about 4 voices and other things needing modulation. However, even then it is probably overkill.
As much as I don't want to get rid of Taiko, it does take up too much space so I think I will replace it. Stages will probably be a lot better use of the hp than the Megaslope. For vcas I think I was going to use the tangle quartets as mixers/utility, and then the exponential vcas for audio. Not sure if that makes sense, but I may have gone overboard. I am taking suggestions to heart in a duplicated rack, even removing the Castle to see what can take its place.
Thank you for the advice!