Not really. Since the 08-09 season (since there is only a 2 month difference in age between them, age isn't a major factor):
Clarkson: 0.25 GPG (0.907 G/60 at EV adjusted for ZS), 0.605 A/60 (0.259 First A/60), 0.43 PPG (1.51 P/60 at EV adjusted for ZS), 17.602 iCorsi/60 after ZS adjustment
Grabovski: 0.27 GPG (0.907 G/60 at EV adjusted for ZS), 1.210 A/60 (0.870 First A/60), 0.61 PPG (2.12 P/60 at EV adjusted for ZS), 16.634 iCorsi/60 after ZS adjustment
While Clarkson has slightly better puck possession numbers with a poorer SH% than Grabovski, the two posted the same goal rate and Grabovski was far and away better at passing the puck to his teammates than Clarkson. Before you ask about teammates, during that time-span, the majority of Clarkson's time was with Elias and Zubrus/Zajac (very close in TOI) while Grabovski's time was with Kulemin and MacArthur. When you consider that Clarkson's contract is only $250 K cheaper than Grabbo's was, there is no way you can say that Clarkson is paid exactly how he should be while also saying that Grabovski was overpaid.
Also, technically, the Leafs replaced Grabovski with Bozak, who is a far inferior player relative to Grabovski it's not even f***ing close.
I didn't want them to go after Weiss, either (reminds me too much of Tim Connolly), and I would have been fine with Clarkson at a slightly cheaper and much shorter contract. 7 years for someone like Clarkson is WAY too long.