player level doesn't mean anything. I'll gladly vs anyone on tournament rules (level 5 units) and not choose anything unlocked after level 10 for NOD and 14 for GDI and still have an answer for every unit you bring.
99.99% of complaints about a unit that someone else has that they didn't and had to fight and didn't have an answer for was their own poor deck, and nothing to do with the unlock system.
Feel free to attempt to change my mind, but every unit as a counter that is available very early on.