I guess it can be done...

From http://en.wikipedia.org/wiki/Eddie_Izzard

Marathons

On 27 July 2009, with only 5 weeks' training and no significant prior history of running, Izzard began seven weeks of back-to-back marathon runs (with Sundays off) across the UK to raise money for Sport Relief. He ran from London to Cardiff, to Belfast, to Edinburgh, and back to London carrying flags of England, Scotland or Wales depending on which country he was in, and carried a self-designed green flag bearing a white dove when in Northern Ireland. The blog Eddie Iz Running was a document of his road running marathon, in which he ran 43 marathons in 51 days. He completed the run on 15 September 2009, after having run at least 27 miles each day, 6 days a week for 7 weeks straight, covering more than 1,100 miles across the UK.^[37]Izzard received a special award at BBC Sports Personality of the Year 2009 for his achievements.^[38]

Izzard ran his final marathon in five hours and 30 seconds, narrowly outside his projected time. However, had he not stopped and waited 20 minutes for his film crew to catch up with him he could have finished well under his target time. In March 2010, Izzard took part in the Sport Relief Mile event.^[39]

Following the completion of the marathon runs, Izzard has started training to take part in an Ironman Triathlon, saying he has become fascinated with fitness "because there's no point in throwing away all that training".^[40

It is highly individualized and doing back-to-back races can sometimes be motivational and necessary to remaining focused on your goals.  Just remember that you are your own best advocate and the ultimate coach making choices about training, endurance and the best methods to achieve performance.  Every race should add confidence and preparation for the next challenge, and if scheduling those consistent events maintains your personal objectives, then do as many as possible.  I certainly share your passion for entering races whenever available.  If you are doing a half every month next year, add in some 8k and 10k competitions to assist in your training. 

Best of Luck!

Make week 9 your last week, and  do week 7  and 8 twice. You are not going to lose or gain much you just don't want to be flat or injured on race day.