You said it yourself,,,,,, hot, dry summers.  They will do fine in a wetter than average summer.  Get a typical Texas summer where it goes a month without rain and your poverty peas won't need a truck to haul them to market.

Oh yea,  they are just as susceptible to root rot as cotton.  And don't think that 10 years of no cotton and the root rot will be gone.  I've seen it hang around for a couple of decades with only milo grown on the farm.