we found the house easily with the old man's leading.这句话为什么最好用the old man leading the way?

we found the house easily with the old man's leading the way.we（主）found（谓）the house(宾）easily(状）with the old man's leading the way(状）这个结构中the old man's(不用加's)应该是 with the old man...为什么这个结构中the old man's(不用加's)加's就是所有格了。在这个结构中，leading是宾补，是现在分词充当宾补，不是动名词充当宾语，所以，就不能加's。动名词充当宾语时是可以加的。比如：He suggested the old man's leading the way.(他建议老人带路)