The description of what you want sounds defined enough and the modules are well thought out. You also have enough VCAs and modulation sources in my opinion. You say you want to be able to make generative music - is this also your main goal with this rack, or do you want to create other types of music as well?
A few things that I've noticed, maybe you thought about these points already:
- You say you want to be "able to connect with external gear as needed", what kind of external gear? The options I see are optical and USB on the ES-8, 6.3mm jack in on the A-119 external input and XLR on the Transmit 2. Maybe it'd be wise to add a stereo 6.3mm jack in/output module, like an fx send/return or something. But again, depends on the type of gear you want to connect with.
- There are not a lot of trigger / gate sources from which you can synch / reset / sequence all your envelope generators and LFOs from. As far as I can see you only have eight outputs from Pamela's New Workout and six from Euclidean Circles (or four if you link the first two channels). This might be okay for you but I'd say that the clock sources on pamela's are used up quickly, you already need at least three to six to sync and reset the Metropolix, René and Euclidean Circles. In generative / ambient music this is less required but if you want to keep everything in sync maybe a second Pamela's New Workout + Pexp-2 would be good to have for some extra time-synched stuff.
- The go-to module for generative music is Music Thing Modular Turing Machine. You could also have this functionality in Ornament & Crime but it might be worth a look.
- You have seven voices and two main sequencers with (AFAIK) two output channels each. This gives you room to create melodies from LFOs, envelopes or shift registers such as the Turing Machine, but these melodies need a quantizer (at least if you want to use traditional scales). You only have one two-channel quantizer, which, if you focus on generative or non-tradional sequencing, might be not enough for what you want (although Ornament & Crime can be a quantizer as well).
Full disclosure: I'm fairly new at eurorack with only two years in.