I didn't watch season 4 and only started on season 5 as DS2 was watching ( He's sadly got no time for it now so I've lost my viewing companion.)
I think that the production team knew that Adam Collard as an older, assured man would work.
Also, very like Ekin Su he wasn't afraid to make unpopular decisions to create drama.
Casa Amor for the ladies was a wash out this year because they put in young boys not interested in a relationship.