Troll warlord has 2 forms, melee and ranged. He also has 2 whirling axes abilities, melee whirling axes and ranged whirling axes.
In melee form, he can only cast melee whirling axes. In ranged form he can only cast ranged whirling axes,
In theory this sounds nice, a hero that rewards decision-making based on what form you want to be at any time and in that form you can only use that form-specific ability.
In reality however, it's a myth. The reason is simple. Troll warlord can cast ranged whirling axes in melee form and he can also cast melee whirling axes in ranged form. All he needs to do is press 3 buttons instead of 1 (switch form, cast, switch form back). There is no penalty or drawback at all to doing that.
In other words, if troll warlord had BOTH melee and ranged whirling axes available to be casted REGARDLESS of which form he were in, it would make absolutely no difference to what troll warlord can do. It wouldn't even be a buff to troll warlord. It would simply be a quality of life change, instead of pressing 3 buttons you can press one.
So in essence, this is my small complaint about troll warlord, his whirling axes ability is complexity for the sake of complexity.
For example, imagine if sven's storm bolt you needed to press 3 buttons instead of 1 for it to go off. Would it be harder to use? Yes, harder and more annoying. Would it be a good change? No, it is complexity for the sake of complexity, and that's not good game design.
I know Dota is supposed to be a harder and more complex game than league of legends or whatever, but there's the good kind of hard (e.g. strategically complex) and there's the bad kind of hard (finicky and tedious for no real reason)