At arsenal with Wenger he will always be a plan B mate, Wenger is too wedded to his system to change that, Giroud whenever heavyweight a run of games as a starter - both before arsenal, for France, and in the periods at arsenal when he starts a run of games, he has performed very well.
There's a reason he starts for France - because none if there other strikers would suit griezman half as well. And that says a lot in itself.
I have little doubt if we got him, he'd be one of the signings of the summer by any team, and would be that focal point the team needs post lukaku, but one who suits the system and supporting players better than Rom did.
The above becomes especially true if sigurddson arrived as those two would be an absolutely a lethal combination.