Most tanks are quite simple to drive, since they usually have two turning sticks, a gear stick, and then accelerator, brake and clutch pedals. The difficulty lies in using the main gun properly (the "manual" sights for the main gun aren't as simple as the point-shoot-repeat ones in OFP, quite hard to explain what they look like, but it's damn complicated unless you're a trained tank gunner), and maintaining the beast, especially if it's a Western tank (the Russian T62 had a modified bus engine, so anyone who'd seen an engine before could fix it, within reason).