Re: Marathon #2 and #3 in the same month?
Oooh, marathons four weeks apart. This is my specialty :O).
corland14, you can do this. These marathons are far enough apart. The key is to pick the one that is your A race, and treat the other one, as you say, like a long run or victory lap.
I love marathons. Just love them. I run a marathon or 50k about once a month. Four weeks is plenty of time for me, but I am not exploring the limits of my capabilities on any of these runs. If I want to PR, I will take a break for several months leading up to it.
You have the absolutely perfect attitude in your first post. You can do both of these if you treat the first one like a long run, and have the personal discipline not to get caught up and race. The only goal you should be shooting for is your designated long run pace. If you ran hard for your 4:06 PR, as you say you did, I'm not sure trying to better that time qualifies as a reasonable, conservative way to run the first one, but you know your this-year fitness level better than I do. Your goal needs to be simply to complete the run and get to the starting line of #2 healthy and energized. I agree that not kicking it in should help a lot. Don't taper for the first race more than a few easy days, take a week with half milage afterwards, then get in one solid week of training and start your taper for #2.
Alternately, you can race the first one, shoot for that PR, and then cruise through the second one as a victory lap, just to experience the day and put another notch in your belt. There is probably a higher chance of injury with this plan, however, because it just takes a while for your body to be ready to go long after giving it all you've got over the full marathon distance. Perhaps the courses should educate your decision on this one. Also, you may choose to race the first one, and get hit by some terrible weather system the day before, and throttle back your goals. Race number two, in that case, is a backup.