As long as the battery physically fits in the car and weight/bulk is not a problem(ie. sanctioned racing), you can never have TOO MUCH capacity/discharge rate. You'll just have extra headroom. As stated, it's the "S" number that matters for charging, not the "P" number. FWIW, I think there is not much reason to go to a 2S2P setup over a 2S1P setup these days. The more cells you have, the greater potential for imbalance among them.