It’s a voice-conflict thing for sure. The solution would be not to worry about the same voices being used. Better that than no voices, or the horror of the offline ones…
On a side note, I just took off from KMWH using FSLTL (plus AI ground and flow) and a GA traffic mod. The airport was very busy with GA traffic and the ATC did a magnificent job - we had landing GA on the small runway 18, departing traffic on 14R and also bigger stuff landing 14R. And all was handled well by the ATC. All really quite impressive.