I have one in the frames that I am quilting ( I quilt by hand, so it is a slow process) and one that I am in the process of piecing. I will not start another until I have finished and removed the one in the frames and then placed the pieced one in the frames and have it ready to start quilting on. Then I will begin piecing the next one. Doing more than that at one time, and working a full time job, and caring for a house and garden is more than I want to commit to. It would just place a lot of stress on me, and I am determined that quilting will remain an enjoyable past time for me.
I guess people who machine quilt or send the tops out to be longarmed can move along at a quicker pace. I just feel good about doing the whole thing myself, so I have to live with the time factor. Either way, I think you will accomplish your goals if you prioritize which quilt should be finish first, then do it. Then take the next one and do it. On down the line. Good luck.