it really is down to you to convince them of the quality of the design, some times the old school guys need to be avoided and the head of the office contacted directly (from experience), i've actually done an application where we had to wait until a certain officer went on their annual leave before submitting!
Which is all time. Iv always done these as commercial ventures, so maybe you on behalf of clients have more time, us when we do them we dont want half a mil upwards tied up for a year waiting for some unreasonable **** to have his holiday.
All i can say is you have a great council to work with. Councils in Kent / Essex / Surrey and Sussex have all been hard work, with absolutely no chance of picking and choosing which planner or planning board it goes to.