How many nights do you have? That is the best way to plan an itinerary.
Where are you coming from? It's important to know if you will have jet-lag. Do you plan to spend any time in Madrid?
Please remember, the city is Cordoba, not Cordona.
So, are you flying into Madrid and home from Seville? If so, I like the order of your itinerary. That is basically what we did, although we also spent time in Malaga, so after Granada, we went to Malaga, and then to Seville.
Why are you picking up a rental car in Cordoba? It will be next to impossible to drive in Granada and to find parking. I suggest taking the train or ALSA bus from Cordoba to Granada. You can also take the train or ALSA bus from Granada to Seville. However, I see you want to stop in Antequera and Ronda along the way. I think your trip will be rushed if you stop in Antequera and Ronda, and it's certainly easier to use the train or bus from Granada to Seville. If you really want to make these stops, then pick up the rental car in Granada, and drop it off in Seville.
Recommended number of nights: (assuming you have 7 nights)
Cordoba - 2 nights
Granada - 2 nights
Seville - 3 nights
OR
Cordoba - 1 night
Granada - 2 nights
Seville - 4 nights
The train from Madrid to Cordoba is about 2 hours.
Bus from Cordoba to Granada is about 2.5 hours. Not sure about the train.
Bus from Granada to Seville - I think it's about 3.5 hours.
Hope this helps.