Henry was versatile, and featured in central midfield, wide on the right and at right back, while IIRC Joe Royle later used him as a centre back for Oldham. He was the kind who could come in and do a job but he wasn't really outstanding, as suggested by the fact that he never played in the top flight again after leaving us. Played on in the second tier for a long time, though.
Mal could never really find the right formula in his second spell at City (not surprising after the insane transfer activity he and Swales pursued), so the team was changing loads all the time. All kinds of players would be brought in for a few games and then dropped again when they failed to make an impact. I suspect that such an environment helped Henry to get games because he was a lad Mal could rely on to be fairly steady among all the chaos.
After John Bond took over, the midfield became pretty settled, the manager usually favouring a four of Hutchison, Gow, MacKenzie and Power. That combination had decent balance, and Henry could only get a game in the middle in the League Cup, when Hutchison and Gow were cup-tied while Power tended to play left back in place of the also ineligible Bobby McDonald. I remember, though, that when Ray Ranson got injured Henry did fill in a few times at right back and he looked decent enough for there to be some talk in the press in the lead up to the 1981 Cup final that he'd be selected in that position against Spurs. He wasn't, and was then sacrificed in what was intended to be Bond's 1981 summer upgrade (Henry, MacKenzie and Dave Bennett plus a few fringe players left, with Kevin Bond, O'Neill and Francis coming in).
Shinton was an odd signing given that we bought him when he was 28 and he'd never played in the top division, racking up over 300 league appearances for the mighty Walsall, Cambridge and Wrexham. Actually, my best mate from university is a Wrexham fan who watched them in that era and, at that club, Shinton is a bona fide legend. However, that's based on his achievements in helping the Welsh outfit to reach the second tier of domestic football for the only time in their history, then contributing to their survival at that level. He just wasn't equipped to handle the step-up in standard when he came to us, and it became clear pretty quickly.
Why Allison thought the player might be able to cope with it, I'm not sure. We've discussed Mal's second coming on here before, and I think a lot of us agreed that much of what went on was ego-fuelled, with the coach wanting to rip apart the old team so he could be hailed for creating a new one. My best guess with Shinton is that it was an attempt to pull off the same trick he managed with Tony Book nearly 15 years before - take a player who's plugged away for years at lower levels, make them a top division star and thus gain credit for being a visionary.
The fates of those two players at Maine Road, however, stand as testament to the differing quality of Mal's work in his two spells at our club. I only remember the second, and it was a crazy, crazy time.