With B&S declaring bankruptcy, Subaru out of the OPE business, Kohler making engines in China for consumer-grade gear, it might be Honda or the Chinese copies on the consumer end and Kawasaki giving them competition on the commercial end.
Those Chonda engines are surprisingly good once a little TLC is done. The Chinese picked a good, proven design to copy, the Honda GX engine. Kohler’s Courage and XT lines are also Chinese, so were Subaru’s last OPE engines. I have a feeling it’s the same ODM who makes the Kohler/Subaru engines, and the Cub Cadet/Toro in-house engine looks similar.