Okay, you're right. On the 2/3, would 8/8 tph each off-peak work for Wakefield/Dyre and 12/12 tph each work for peak? 16/24 tph off-peak/peak is probably all the operating costs New Yorkers are willing to pay to send trains from 241 or Dyre to Brooklyn College.
8/8 is approximately the current midday split. Current rush frequencies on the combined 2/5 are about 20-22 TPH (about 12/10 towards WPR including the put-in 5's); this is mostly limited not by reverse-branching but by the terminal at Flatbush, hence the 8 to New Lots in the MTA's Rogers fix plan.
That plan notably assumes the existing service patterns on the north end. In short, to take full advantage of any capacity increases from deinterlining the Bronx IRT, precisely one reverse-branch (New Lots) is absolutely necessary to absorb the service that cannot terminate at Utica or Flatbush.
Even if WPR & Dyre aren't getting service increases through de-interlining, Jerome is, which mitigates a little of the overcrowding at GC/149 transfers from de-interlining IRT Bronx. It is likely to get 16-20 tph off-peak (great for Yankees games) and 24-26 tph peak.
And it's not just capacity that's a problem with the interlining -- it's reliability from so many track merges on such high frequency and long length services, and delays cascading. It's longer dwell times from folks shuffling around waiting longer for *their* train.
Anyhow, does this means that de-interlining Rogers (read: cutting open Eastern Pkwy, ugh) is likely a predicate for de-interlining IRT Bronx (as well as SAS connecting to the West Side Lines). I do think Nostrand should go to KP (water table, I know), and Utica to Kings Hwy or Flatlands Ave.
P.S.: I should add that sending the 4/5 to Jerome and 2/3 to White Plains Rd./Dyre makes tons of O/D pairs much faster -- particularly off-peak -- as the frequency increases, and the transfer penalty lessens.