Was Fortinbras a good role model for Hamlet? Or a bad example?

Hamlet (speaking about Fortinbras):

"Examples gross as earth exhort me:
Witness this army of such mass and charge
Led by a delicate and tender prince"

Fortinbras' father was killed by Hamlet's father THIRTY YEARS AGO. Fortinbras is a coward who waited 30 years, until after his father's killer died, then raised an army of "lawless resolutes" to dishonor his father's pledge (that a plot of land should go to the victor in the duel between Fortinbras' father and Hamlet's father).

If Hamlet had really followed Fortinbras' example, he would have delayed for 30 years, then raised an army of "lawless resolutes" to steal Denmark from Claudius' successor.

Fortinbras may have delayed until the 'seal'd compact' between the royal fathers had receded in popular memory.

Did slay this Fortinbras; who, by a seal'd compact,
Well ratified by law and heraldry,
Did forfeit, with his life, all those his lands
Which he stood seiz'd of, to the conqueror;

Or thinking by our late dear brother's death
Our state to be disjoint and out of frame,
Colleagued with the dream of his advantage,

or because

Norway, uncle of young Fortinbras,--
Who, impotent and bed-rid, scarcely hears
Of this his nephew's purpose,

Or, in a more speculative vein, if Fortinbras had attacked while Hamlet's father was still alive, Hamlet's father might have challenged him to a personal duel.

But Fortinbras held a "weak supposal" of Claudius worth. He was confident that, in attacking Claudius, only common soldiers would have to expose "what is mortal and unsure / To all that fortune, death and danger dare."