Well, when you look at this, there's definitely some shortcomings. For one thing, using the ADSR/VCAs isn't an economical use of space; it would make MUCH more sense to add several linear VCAs on a single module, then solve the other problem present here by adding some more modulation sources to mess with them. I think you're also concentrating too much on distortion effects here...you really only need A distortion device, but a wavefolder somewhere up the signal chain would actually make sense so that you can get more elaborate and controllable (and yes, distorted) waveforms that way, so DO keep the Wavefolder. And there's other issues as well...a lack of controlling modules such as attenuverters will hurt you here, for example.

I think the big problem here is that the Erica drum functionality is overriding the ability of the top two rows to be used both as a complement to the Erica modules and as a self-contained synth on its own. This is why I tend to tell people to NOT build a Eurorack drum machine...the modules for each drum voice are never space-economical and the operating needs of that modular setup are often fairly divergent from what a modular SYNTH has to have to really open up. You might want to remove all of that from the build before continuing so you can get a clearer idea of what those top two rows SHOULD be.