Hey I'm a brand new Mini owner.. Mini's not new, just me. My front tires are completely bald, was thinking about replacing them with Dunlop SP Sport 5000A DSST Run Flats and leaving the almost new Goodyear Eagle NCT 5 EMTs on the back. Both sets are 195/55R16..
I noticed some posts about mixing run-flats and regular tires, but not about mixing brands.

 

You can mix different runflats in the same size but usually to prevent hydroplaning risk in the wet you put on the best tread tires in the rear and rotate the worn tires to the fronts.

You'd get less uneven front to back wear by rotating tires every 4000 miles although some owners don't do this. Just keep the Dunlops on the same axle front or rear when rotating.

Keep tire pressure up as well.

Don't mix non runflats with runflats on the same car.

 

I decided to go with the Bridgestone Potenza RE960AS Pole Position, and just forgo the run flats altogether. Got 'em today.. seem kinda soft

 

Those are good street tires and balanced between dry and wet handling with comfort and longer treadwear.

They are not for the track so that is why they seem kinda soft.
Most All Season tires are going to be a bit softer except maybe for
Goodyear Eagle F1 All Season.