I think the best defense against wrestling for a BJJ practitioner is nullifying his wrestling. We need to accept the fact that it is not easy to sweep a wrestler since they train all their lives to take people down, not to get taken down or swept. Also going for submissions is leaving the BJJ practitioner open for punches to the face and TKO. Even if the TKO does not occur, the BJJ guy takes damage which takes away from his heart, strength and stamina. So perfect way to counter a wrestler is to work on recovering guard and locking him tight in there. not going for anything, but just hold him there. The fight will get stand up eventually. If the fighter goes for a sweep or submission he leaves him self open for attacks and also resets the internal clock of the referee delaying the stand up.