Not necessarily. You can't really judge that based on this statement. I say that because I'm the youngest of 6 brothers and while I had my moments of being a typical little boy (playing in the dirt, exploring the woods, trucks, playing Army, etc) I was also a very shy child, I was never into rough and tumble play neither with my brothers or friends, I also had a hard time injecting myself into play with other boys because of my shyness. Add to this that he probably didn't really have time to bond with his older brothers since it appears they weren't a regular fixture in his life, which would make injecting himself into play time with them even more difficult.
Another dimension to this is the fact that Lucas probably had, at best, a somewhat strained relationship with his biological mother and since his father was gone for weeks at a time I wouldn't be surprised if he wasn't dealing with some separation anxiety and since EG was his primary caregiver he would have stuck to her, afraid to leave her side out of fear she might go away also. I had this problem myself as a little guy. One of my brothers that I was very close too died, after Pete passed I became even closer to my father who then died a year after Peter. As you can imagine, my little world was shaken to it's very core and as a result I became very close with my mother to the degree that I had a hard time leaving the house for a few years, afraid if I left that something would happen to mom or that she might leave me also.