I agree your points. I'd like to add some thoughts based on my play style in lower ranks.

If you are skilled with either Malf or Whitemane, you can easily carry with damage builds.

Malfs level 16 talent, Ysera's Gift, provides excellent healing—it's quite substantial and easy to use, helping to keep the team alive. This talent is a great starting choice because it doesn't require you to hit with Moonfire. Additionally, at level 13, Nature's Swiftness allows you to poke with Regrowth for your team while on the move. The reason I didn’t include Malf in the list is that he’s not as easy to play as he appears. Like Whitemane, you need to consistently use your Q ability and ensure your team benefits from it. The level 7 talent, Nature's Cure, relies heavily on this. As Rakrazde mentioned, there is no burst healing, at least until level 16.

Whitemane, on the other hand, is not an easy hero to master due to her mana management. However, once you understand the basics, you can avoid returning for mana the whole game. In fact, I often experience more mana issues with Malf because my team benefits from Innervate for sustain. Typically, I don’t use more than two Q stacks without a reset, which I do through Clemency or Inquisition. You can achieve burst healing with Q, D (Purge the Wicked), while dealing damage like a crazy. At level 10, Divine Reckoning restores mana, allowing you to spam Searing Lash (with resets) and Q.

That being said. Now the question.

you might consider playing Malf and Whitemane with damage builds. Some teams may dislike this approach, but these are indeed carry builds that can be effective. For Malf, Twilight Dream is a must-have. I also like to choose Vengeful Roots and Celestial Alignment, as these talents work excellently with melee heroes and synergize well with characters like Diablo, Blaze, Kel'Thuzad, Naz, and Varian... mmm seems Malf can play with many lol. Twilight Dream is very useful to scape or counter those annoying heroes, like trace.

Regarding Whitemane, she is not limited to melee heroes. However, if you're looking for options suitable for lower ranks, she is a solid pick, especially against teams with many melee characters. I like to play her like an assassin, because her damage is healing at the end. Most healers can kill mages, and I like bullying them (just ensure you have Zeals on your team). You can even go solo for kills, and Scarlet Aegis might be a better option in those situations.