[quote=So Boerd]
The principle remains the same, just with a whole lot more oomph. Fast (Even modern tanks can go 60 mph), armored, but vulnerable to multiple opponents or Z-axis attacks.
[/quote]

Here's the difference between a tank, and a character wielding a weapon that shoots tank shells; the character can punch, -dodge tank shells-, do backflips, and move freely in any direction he wants. A tank can not. 'Tis why they are a bad alternative. That lack of movement capability spells certain defeat against all but the weakest of characters.