Just because your dawg is smaller do not think he thinks he is. After their growth plates have closed, they can run marathons, go on long walks, swim and anything those larger dawgs can do but most times better as they are more able to move on a dime.
But it is important to socialize with larger, friendly dawgs to help your dawg to become balanced.
Expose, expose, expose and it will pay off if you do it without the coddling no matter what the reaction.