I'm in a similar situation. In my opinion, it is IMPOSSIBLE to finish banking (let alone get to ~90% banked) by a June exam if you just started now. Does anyone else have any insight/experience? I called the FC company and they were not too helpful and told me "everyone is different".
There are about 1100 cards, with an average of about 8-9 concepts (aka questions) per card, therefore about a total of roughly 9,000 concepts/questions (please note, these are my approximations based on the fact that I've banked 25.4%, with 2189 concepts so far... [therefore 2189 / 0.254 = 8,983]). When I called FC, they did not know how many concepts/questions they had. Assuming about 9,000, you'd have to bank about 100 new concepts/questions per day to get 100% banked by May (about 90 days). That doesn't seem like a lot. But, if you truly introduce 100 new concept/questions per day, the daily review # keeps building up and you'll be needing to do hundreds of review questions per day, not to mention flagging 100 concepts/questions-worth of new cards. Despite likely not being able to bank all of FC, I'm still doing FC because it is really helping me. I'm focusing on important topics, especially those I'm weak in.