You are definitely not talking of the same game than Shaefer did to the Danish magazine that Sian was kind enough to translate ( I already linked it twice to this thread, so forgive for my laziness ). Shaefer explecitely talked about wide fronts of units side by side. You can twist history in the any way you like, but there was simply no huge fronts wars until maybe the American Civil war ( the napoleonic wars were definitely more SoD type than front type , for a example ). This has nothing to do with leaving troops behind for garrisons and such, because , if they had made a more refined mechanism in Civ IV, this could had been acheived even with the SoD system ( say, any combat troop would need x auxiliary regiments for the logistics, that would need to be in the cities or atleast in controled territory ).
To be honest, you are simply stating your distaste for the Civ IV SoD tendency. I can agree with that, but that is not the same that saying that a unit per tile is a better system or even anything remotely resembling historical examples until maybe 2 centuries ago.And, as far as we know, the game might allow a huge front of troops ( say , Barbarossa wide ) in classical ages or some other nonsense equivalent to the Civ IV SoD ....

I'm sorry, but I cannot find it explicitly stated that there will be exclusively fronts. Actually, I don't even see if the original post (translation of the review by Sian) says anything about them.
I do not have a distaste for SoDs. Heck, I've been playing with them for a very long time now. I'm just saying that PG style is attractive too!![]()
On the official Civilization V site, in the features section under the heading,"Huge Battles", it mentions that," wars between empires feel massive with armies spreading across the landscape" This strongly suggests that the majority of combat will be in fronts, and the screenshots showing combat seem to only confirm this.
Also, how will one unit per tile change strategy much either? All this will degrade into is having a few giant battles, and then once one side's military is decisively broken, it will turn into the other side marching from city to city, assaulting it, while fending off a few minor attempts by the losing side to try and turn the tide, which, unless something drastic occur(Fx:Getting allies), won't have any effect.
Anyway you handle it, it will come down to is some giant, decisive battle or two, and then the mop up, and because cities are the only thing of major value, and seem to be still in Civ5, it will consist of such sieges seen in Civ4, except that because you can only have a small garrison in each city, whatever units the losing side produces will be thrown uselessly at the far more numerous side. Really, making it so units aren't necessarily killed in one attack would provide more of a change strategy wise.