That could be true to some extend. Wouldnt be surprised.
I dont particularly like it when Eamon makes his suggestion to make Alistair king and speaks about duty and other nonsense, but was there any other choice to stop Loghain? As Eamon says we would waste lots of troops if we wage full war against Loghain and while I would really like to assasinate him and be done with it, it would look really suspicious if we would step in right after Loghain dies. Could there have been other ways that dont involve lots of bloodshead or something really suspicious that could make us look bad?
I see it as him using Alistair. Partly to stop Loghain but partly as a grab for power as well as some revenge. When he says it is his duty, yes there is some truth to that but nobody had a duty to Alistair, did they? If his royal blood was such an important thing, then he should have considered it before sending him off to the chantry. In fact, if Alistair were not standing there what would he suggest you do? Try to get him from the chantry?
It's just another one of those opportunist moments we see. Like if you decide to take the golems to a degree you are being an opportunist strengthening your army beyond men. If you side with the werewolves and don't cure the curse again you are being an opportunist unless it is out of racist spite. Wardens are the ultimate opportunists in recruiting and in using whatever they must to stop the blight.
But there is a whole undercurrent of people with power especially acting out of opportunity. Vaughn takes the wedding and his father's absence as his opportunity. Howe takes the smaller force at the castle as his opportunity. He even sets it up to a large degree. Loghain takes the battle at ostagar and Cailan's death as an opportunity. Duncan in every opening turns it into his personal opportunity to get a new warden. Irving uses the mage as his opportunity to get back at the Chantry. Behlen uses the family situation to manipulate the siblings and create an opportunity. I'm sure there are more but these are what comes to mind. It's really all about opportunity. And Eamon is just another one who uses the situation as an opportunity. It's pretty clear he doesn't really give a damn about Alistair. It's only the precious bloodline and also, he knows alistair doesn't know how to be a king and is far from king material (even Cailan wasn't king material if you hear what anora has to say though she's kind about her loving husband). And Eamon knows this which is exactly why it is even more cunning. Who do you think Alistair will turn to? Well, he appoint Eamon his regent if you don't marry him to anora and there it is. If you marry him it's still the same with Eamon as the regent. If you do US, I guess Anora becomes queen since he doesn't kill her and Eamon gets the boot, but Eamon, with Alistair on the throne alone, just ended up ruling Ferelden, did he not? Do you think that wasn't part of the plan? Of course Alistair would turn to his uncle.