I might be totally wrong but I've been browsing this forum for years but surely it would make sense for

6118-21 to go to Percy Main for the 1/1A
and
6 (I think) Streetlites for the 19 and anything else that uses full size singles - not sure how many would be needed.

Then send the Omnicity's to Riverside / Chester Le Street with the rest of them to see off the L94's there to keep them together.

The fact that the 19 hasn't been branded as part of the little coasters and the fact 5419 was there on Friday / Saturday (I got it on the 19 - not sure it's still there) would suggest there's plans for them to go there at some point plus it makes sense as it upgrades it to Euro 5 and stops the mixed allocation currently which can't be fully minibus because of it interworking with misc contracts.