If Democrats are doing the counting in Democrat areas, then who the hell do you imagine is doing the counting in Republican areas?
Anywho
In reality the counting is going on with multiple observers from both parties, with flagging systems in place for supervisors to look at questionable ballots, as well as the local and national media actually covering all this from the ground, etc. etc. etc.
It is inconceivable that a massive voter fraud operation could take place without word of it leaking in some way with so many eyes and hands on the process.
Tbh my takeaway is to be pleasantly surprised at how regular this voting process has been in a high-turnout, high-emotion, pandemic election