Please give us more details on how you arrived at this conclusion. Thank you.
(Please note; nobody is contesting that the Berserker deals top-notch damage. The issue with the subclass is the cost of its main feature. So I'm having a real hard time understanding the focus on the feats.)
Unless you're talking about the "guide to enabling my bonus action to make an extra attack" optimizing discussion. In which case I would have assumed Frenzy, eating bonus actions,
interferes with GWM or PM, which indicates the
opposite of "equalizing the two subclasses", which is why I'm asking you for more data...
Others have rightfully looked at other feats to substitute for Polearm Master for the Berserker, but I thought it would be fun to compare the Berserker to the Totem Warrior with the exact same feats and I was sorta surprised with the results. I am assuming Polearm Master is taken at lvl 1 by both humans. Also I am using the lvl 3 Bear totem ability for this comparison (I am a strong fan of Wolf as well)
Lvls 1 and 2, they are both identical
lvls 3-5 the Totem Warrior warrior comes out better for the most part but only while raging. When the Berserker is Frenzing, they will do more damage but suffer some negatives afterwards due to exhaustion. (also I am having the Berserker carry a GW on her back, and only pulling it out while Frenzing).
lvls 6-13 This is interesting because, this is where the Berserker gets Mindless Rage, so it is careful to discuss all the situations.
While not raging they both appear to be equal, but they are not. If they are charmed or feared while not raging, the Berserker can just rage to suppress the effect. On the other hand if a dragon does a surprise breath attack, both would get damaged because the Totem Warrior can not react with damage resistance rage to prevent damage.
While raging-the value depends on how you rate Mindless Rage vs Bear Rage damage resistance. I rate Mindless Rage higher, because being charmed (dominated is charm as well) or feared, means less time on target and more chance of a party wipe or even worse dominated, which could easily lead to a party wipe. Damage resistance to all but psychic damage with the Bear Totem is still very strong, but remember you do have the highest hit points in the game, so you resisting damage isn't as important as it is for others, but still it is a strong ability.
While Frenzying the berserker can drop the polearm and pull out a great weapon and do more damage than the Totem Warrior, this should only be used very sparingly because of exhaustion.
After Frenzy- Advantage Totem Warrior, which is why Frenzy should be used very sparingly, for the most part in final show downs or when a wipe might happen if everyone doesn't go all out.
Lvl 14+ Here is also subjective, but as far as damage, Retaliation is better than the options presented for Totem Warrior (I do really like the Totem Warrior abilities here, but for damage its obvious).
Analysis: lvl 3-5 goes to the Totem Warrior
Lvls 6-13 advantage goes to Berserker
Lvls 14+ even more advantage to Berserker
The key is to only use Frenzy when you really need it.
Note that this is just a damage comparison and does not look at out of combat utility (which I am very strong supporter of). Also, I do not believe that either option is just better, party composition and preferred playstyle out weigh any of these factors. I am just trying to show that the Berserker is very viable in comparison to the Totem Warrior.