During certification , use of reverse is mandatory on a wet runway and not a dry one. This might give a higher MTOW on a wet , due to actual lower accelerate stop distance.
However Accelerate stop distance on a wet runway is the higher of : ASD dry , ASDwet , ASD wet(N-1)
Although Actual accelerate stop distance on a wet would be lower than a dry due to the use of reversers ( lower distance means higher MTOW), DRY accelerate stop distance would be retained if higher .
Therefore all speed calculations , optimum and balanced V1 would be calculated to comply with the dry if more limiting.