Tian Feng possessed great foresight along with Ju Shou, and I strongly believe that Yuan Shao would have unified the north if he took Tian Feng's advice on numerous affairs. Remember Tian Feng's advice on Guan Du and Ju Shou's advice on how to unify the land.
Yan Liang and Wen Chou were not just grunts, but leaders on the battlefield that helped lead Yuan Shao's forces to victory in the north. Having two generals, with unmatched power, leading the army can add quite the necessary sting to Yuan Shao's war machine.
Putting aside their desires for personal advancement, Guo Tu and Feng Ji were notable officials and advisors as well.
However, I must disagree with Mao Zonggang in your last statement:
"..... but Yuan Shao was no leader so quarreling it is. "
Yuan Shao was a great leader who ruled with integrity and justice. His only downfall was being torn between his various advisors. Keep in mind his illustrious career serving the Han Dynasty and his decending from a long lineage of high lords and officials. Had he not been a leader, how could have have unified the provinces of Ji, Qing, Bing and You? How could he not have conquered the bandits of Bing and the White Horse General, Gongsun Zan? He also achieved one of the highest victories in warfare - victory without battle - when he took control of Ye.
Next time, I advise you think before you speak about a man you must know little about. For good taste, below are the site's links to Yuan Shao's biographies.