Yea, there's a bunch of enemies with weakspots of various kinds. And not all of them weak, per se. You can shoot the urban crawler in the upper turret and it will jam that turret (which helps against the flak on the higher tiers), but if you shoot it in that big dorsal armor plate it only does 10% damage (unless you use something like miasma whip, since it hits both the armor plate and the main body).
And if you hit the clockwork probe with blue-element stuff it slows down, and if you stack enough of that to slow it to zero it drops like a stone