Stuck compares Glock with Ralf
"In once sentence: Timo's strengths were Ralf's weaknesses," the German, now a motor racing official for the German marque Volkswagen, told the Cologne newspaper Express.
Glock, the reigning GP2 champion, recorded his first podium last Sunday at the end of a consistently impressive weekend at the Hungaroring.
Schumacher, who lost his seat at the end of 2007 and is this year racing in the German DTM series, failed to similarly finish in the top-three throughout last season, despite a salary some 8 times higher than Glock's reported $2m per-year contract.
Stuck believes the two racers' "attitudes" are vastly different.
"Timo is a substantially harder and more consistent worker," the German explained. "It's not just between Friday to Sunday; he lives, thinks and dreams F1, as his bosses such as Dieter Gas tell me.
"He is fully integrated with the team, communicating with everyone — even in his spare time. He has chosen to live in Cologne, to be near the team," Stuck added.
In the personality department, 26-year-old Glock also has the edge over Schumacher, a six time grand prix winner, according to Stuck.
"Their nature? Timo is a chirpy, eloquent type. Ralf could also be eloquent, but also moody at times. And (Timo) has good management. If Ralf had taken some well-intentioned advice, he might not be where he is today," said Hans-Joachim Stuck.