The most suitable routes at Scotstoun for the E200EVs are also the ones that don't need electric buses due to not serving the low emission zone. If the interlink with the 8 was broken, the 16 would be fine for them but other than that it's really only the 81, M11 and M60 they'd be suitable for.
As for Lanarkshire, the only services I'd say are suitable are the 226, 227, 229, 241, 242, 254 and the 266 at a push and you'd also need to break the interlink with the 267 at certain times of the day. As for Dumbarton, it's really only the 206 and 208 they'd work on.
I think First have put themselves in a bit of a hole by committing to them up to now and hopefully there aren't any more after this order due to far better options being available.