Actually, Eldest Cousin was a very capable man, but by himself, he could not surpass Second Uncle's family with Fourth Cousin, Second Cousin and Second Uncle!
Especially since Second Aunt was very competent too, and did very well at work.
This family was really very powerful. No matter how good Eldest Cousin was, he was only one man. And to outsiders, he seemed weak.
He was not the successor even though he was the eldest grandson of the eldest son's family. The second son's family was clearly in charge of the Gu family. Naturally, scheming people made a big deal out of it.
Fortunately, the Gu family had always been very united. It never experienced a split even after so many years.
In Second Uncle's family, Fourth Cousin was always doing exceedingly well in business. Second Uncle's family was not lacking in terms of financial strength.