A proposed improvement

I’m sure there are logical reasons why this doesn’t exist but I just wanted to put this out there. I’m planning for my first marathon in October but in the process I have 2 halfs in April and June. The one in April is too early for me to add it as a B race for the full. My training is currently A- race in June and B in April but it would be great if I could incorporate all 3 so that the recovery is factored in.

Not saying necessarily 2 additional races just a way to start a far out marathon (or whatever) plan and add in an a much earlier B race.