What is the "role" of a fiery vortex that pulls you in. Controller? Soldier? Leader? Damage-Dealer?
Controller. It moves you into a disadvantageous position. Depending on the rest of the powers it could also be a Soldier because it's sticky. I don't see it as a Lurker or Skirmisher since it doesn't want to get away from you, unless it's able to become intangible and power up its next move then it could be a Lurker.
Leader is not a role on its own, its a couple abilities added on top of another role so there could be a version of the Fire Vortex that's a Controller Leader or Soldier Leader.
Roles are over-simplified.
They're meant to transmit information quickly, so yeah, I guess?
What we need are tactics. That's bigger than a role. That's telling you the strategy for using the monster in a fight. Which might be different for different monsters, including things unique to them and also how they'd function in either solo, with a small or large group, etc.
Good news! 4e ALSO had a tactics block after every Monster! Do you think every monster of the same role plays exactly the same with the exact same powers?
The thing with 4e monsters is that their unique powers, which helps define their role, feed into their tactics. If all you do is read the powers of the monster and try to use them as much as possible… the tactics will organically emerge from playing to their strength!
The simplest example is the Hobgoblins who have an equivalent to Pack Tactic and get buffs when fighting next to each other: If you try to activate those buffs then you will naturally create formations and battle lines on the field, reflecting their military culture.
A Monster’s role aid in aiming the design so that their powers are designed to facilitate the tactics that would best match the lore of the monster. It’s all interconnected. And then when you go to DM, you know that putting different roles together will automatically result in a more dynamic and interesting encounter than just 5 identical monsters.
But that conclusion isn't an objective one, is it? I think there are arguments to be made for other roles.
Kind of hard to say without more powers and stats, but monster making is as much an art as a science so... I guess?