Let me explain to you why this isn't a feasible solution.
1. has to merge with the , which brings it close to, if not over, 30tph
2. and have to merge with , which is just under 30tph or so
All of this unecessary merges will without a doubt causes delays. ONLY THE A/C/F lines are affected. Your solution delays the , and possibly the .
"The and tracks are set to the Brighton line."
That makes no sense because those tracks don't connect. That's like saying that the 60th Street tunnel tracks are set for 6th Avenue; there isn't any connection.