With Harrold out for the season, he had to get someone in. Riordan will either make this league look like a piece of piss and rack up more goals than Sean McCarthy's had hot pasties, or he'll flip completely and be back up the road before you know it.
I'd loved to have seen him at Argyle, even allowing for his somewhat volatile nature. In fact I wouldn't have said no to Matt Harrold either. When he's fit, and if Riordan comes good, that's two very good forwards they've got there.