We had Oscar, Tetteh and Williams as our front three, and while it could be argued that Williams doesn't offer too much, he's nevertheless capable as a stand in for Allahyar/Longman. As it happened, we had the exact same defence.
Just my observations, but Coyle hasn't started the season well; he's not a bad player but I'm not sure about his ability to command that right back spot over 46 games. If he proves me wrong, so be it, but if he's still first choice come the end of the season, I'll be surprised. In this division you need your full backs to have pace to compete with the wingers they're up against, Coyle just doesn't have that. He's a good footballer and he'll be good cover, but I don't think he's first choice Championship material, captain or not. The one thing Coyle does have is versatility; when he played at Fleetwood, he was converted into a central midfielder by Joey Barton and he did very well there. I see that as a much more suitable role for him, especially given his passing and crossing ability.
You don't lose because you sit back (which is fairly common in games against more talented opponents), you lose because you concede goals. Truth be told, it could have been more than five were it not for Ingram. In fact, in most of the games this season we've not had much possession (though we have played three promotion favourites so far).
Our defence, while able, is still learning and is wafer thin in terms of depth. If there was an injury to Coyle in training tomorrow, who would cover him? With Fleming injured for however long, who brings quality to the left back position if something happens to Elder? We can't ask kids to step out of the academy and into the Championship at the drop of a hat, not if we're serious about finishing higher up the table. We're clearly bringing in players to challenge the others and to add quality, Christie does that for the RB position.