I didn't think Button was THAT bad now. It's pretty nerfed, but it still should allow that ZiS gun to get one more shot when the tank is low on health right? I feel like it's situational, like if they are near death try and use it like a ghetto snare ability so you can chase it down or keep it in range, otherwise it's not really worth it.
After how much it reduced speed and acceleration got reduced, there's just almost no realistic chance of it working for more than a few instants unless: 1. The Guards are magically like, right next to the vehicle. 2. The vehicle's already engine-damaged, likely making the use of Button then superfluous.
Not to mention as elchino7 said, you'll probably be dropping weapons as the Guards inevitably take fire while doing it which makes you more likely to just break it off yourself so you don't pass Axis your entire armoury.
Still better than Guards having like a 30 radius "Armour DOES NOT go here" I guess though...