Yoshi is probably passive and easy going by nature
I think some yorkies/dogs don't mind not being boss.
Rosco is not a yorkie but he lets Joel get his way with ANYTHING. I try to get Rosco to care more because we planned on him being the boss when we brought Joel home but it's like he likes being bossed by Joel,lol
Don't ask me how a 8lb yorkie can control a 170lb Akita!