be careful not to put yourself to far near the front as you will get shoved and pushed or worse still you go off at to quick a pace and fade badly at mile 10. You wont be on your own pace if you start at the front at wilmslow the calibre of runner is much higher a 1.40 gets you about 700th position whereas i bet it was much higher at macc. you dont want 700 runners coming past you!
as dan says wilmslow has lots of space so you wont get boxed in if you start at the right place.
Good luck, and yes more intervals are needed but make sure you are doing the training at the right paces. eg Easy, slow or steady. If unsure use mcmillan pace calculator to help