I try and keep one dog at each side as they seem to be more excitable if they're up front bustling along in that "I'm sticking to you, cos I'm made out of glue, anything that you can do, I'm gonna do too" way that cockers tend to... 
I walk Saffi on my left and Jessie on my right. Jessie is in a harness and Saffi on a callar and lead. As Saffi is only 7.5kg she pulls but doesnt dislocate my shoulder like JessieKaKa does

Janey