Evaporative coolers work really well in the Southwest where we see average relative humidity numbers less than 30%. I used to live in Oklahoma and I don't think I ever saw a cooling-day humidity less than 70% RH.
Here in the SW, we regularly see a swamp cooler drop air temp 20[°]F while raising relative humidity from 20% to 50%. I would expect in Oklahoma to be able to get a 6-10[°]F temperature reduction while taking humidity from 70% to 85%. Temp drop would be less on a 85% RH day. So, with air at 105[°]F and RH at 80%, your hard work would lower the cooling-tower temp to around 102[°]F. That may be worth it. It probably isn't.
In a lower humidity area, it could very well be a great idea to have a swamp cooler feed air to a ducted cooling system. I don't think that Oklahoma would be a great place to start.
David