Heya, I am Nic and a new member. I have 2 golden retriever boys, Kobus 18 months and Lukas 12 months old. They have some of the basic skills and obedience 101 under the belt so far. I would like to ask some guidance on how to train 2 doggies in stead of 1. Training is harder after we got Lukas and generally stop earlier as they start playing with each other (obviously) . Should i keep one inside while i train one outside, and if so, how long should i then do the specific training exercise, before i switch boys?