It’s not really a problem having so many strategies, it will help you find strategies faster as you are able to skip the generator having to find strategies from scratch. Just make sure to keep them tidy I guess.
What about other pairs and timeframes? You should focus on building these up if you are approaching too many for EURUSD M15.
Also once you have a big collection this will allow you to run the reactor less often and just use the validator going forward to ensure your pools keep passing the validator settings or also if you decide to change your strategy requirements by modifying the acceptance criteria you will have a large group of strategy’s to begin with.
I would pick the pairs and symbols that you want a pool for, build each up and then going forward use the validator to maintain and keep current and the Reactor to top up as needed going forward.