Sadly this statement perfectly defines everything that i despise about the civ series. Then with civ4 they give us this wonderful unit experience platform which you cannot use because of unit attrition and yes, the old spear chuckers killing tanks motto rolls on happily in civ4 so that none of your experienced units are safe or can live long enough to gain all those wonderful experience options!!! (unless you love reloading of course)

I've had no trouble getting plenty of level 5 or 6 units by the industrial era. Most of my units are level 4+ by then and that's plenty strong in that combat model. You can't possibly be losing units against the Civ AI, it's not exactly able to handle the game. Maybe the BtS AI at Immortal - admittedly it's a hard slog at that level, but then, the AI gets so many bonuses on that level. I've never had a spearman kill a tank in Civ 4, ever. This can only happen if you try to attack a full strength fortified spearman in a city with a tank at 5% health. And no, a tank shouldn't always defeat a spearman even at that health, because a tank that damaged is no longer a tank... it's a broken down metal tomb that's out of ammo.
Those who claim Civ 4 games are troubled by spearmen vs tank issues either haven't played Civ 4, or are using some poor strategies.
Besides, there has to be some way of overcoming an opponent that has beaten you in the tech race, if they can't match your manufacturing. Otherwise, if they get to the industrial era before you, they could just pump out 6 unbeatable tanks to wipe out your empire. This is exactly what happens in games which don't scale the unit strength down with health... when I was splaying Elemental, I only needed to build about 3 high strength units for each war front (5 after they fixed the squad strength bug)... no matter how low their health gets, they still have full attack and defence, so none of the AIs minions can bring them down with attrition. As soon as you hit that tech level, you steam roll every opponent with a handful of units.
If i had to pick a game that Elemental was most similar to it would be Rise of Nations not civ5.
Oh come now. RoN may have been better than the usual hack and slash RTS crop, but it was still a clickfest. Elemental is in a better class of strategy than that.