I said flanking is optional? The Panther and the Jackson have the mobility to flank too, the Panther even has an ability for it, but that doesn't mean it's always a good idea to do that or that it's their primary role.
They originally had Flanking Speed at vet 2, which does not really point towards the unit primarily being a flanking unit, but as a way to let it scale against heavier targets that it could no longer effectively engage frontally.
It has an x/-20/-20 penetration profile that is completely natural for tanks.
Totally not comparable to the Puma's profile that doubles from 80 far to 160 close. Not that the Puma is primarily a flanker either.
The T-34/76 has a regular x/-20/-20 penetration profile too, with worse close range pen than any other tank. I don't see how that has anything to do with the M10/Achilles.
The SU-76 simply has higher penetration because it's a casemate with low mobility.
Yes it has the mobility to flank if it needs to, that doesn't mean that that's its primary role. This description does not suggest that or it would've said something along the lines "best used to flank enemy vehicles". Not that Relic descriptions are anything to go by anyway, most of them are faulty.
The M10/Achilles is a very good medium counter because it's cheap and it can outrange them. It can flank heavies too if need be, but that's not its primary or only role.
And that is why it's a good addition to the UKF stock roster, because they didn't have a cheap medium TD to fill the gap between a Centaur/Cromwell and the much more expensive and more geared to towards anti-heavy Firefly or the even more expensive Comet.
I moved the post here since it off topic in the other thread.
Relic had clearly given the role of flanker to certain vehicles. That does not mean the are meant only to flank or that they only role is to flank since unit can fill more than one role.
Flanker units will do so and so vs enemy unit in frontal fight and will do far better if the attack from the side.
They usually combine mobility and high penetration at close range. Example of this is m10 and T-34/76.
Penetration:
T-34/76 80->120 a x150% increase in penetration
(for comparison PzIV 110->125 x113% increase
M10 140->180 a x129% increase in penetration (and gets AP round on top of that.)
(for comparison 170->200 x118%)