If there's joint ticketing then this would be better imo:

306 - Pulled out of Battle Hill
308 - No Changes
309 - 311 Route to Hadrian Park, 309 to Cobalt (Every 15 Minutes), Extended to Blyth (Every 30 Minutes)
310 - Upped to Every 15 Minutes

306/308 - Combined every 7.5 Minutes between Newcastle and Billy Mill
309/310 - Combined every 7.5 Minutes between Newcastle and Battle Hill

There's absolutely no need for a 10 minute service between Blyth / Whitley Bay and Newcastle plus it wouldn't work anyway as it would make the 306/308 run at the same time. Why should Arriva drop down to 6 BPH while GNE still has 9 BPH. I wouldn't be too keen either.