LostSoul
Adventurer
Unless of course this "guess the fluff" dynamic is what you want.
Maybe.
If players knew what fluff triggered their powers*, I think that I want this fluff in this situation to matter. The reason why is so that no one (player or DM) will know exactly how a situation is going to play out until you engage with it. I think it opens up a space for a lot of imaginative input from everyone involved.
The game dynamic that I would like to see isn't about the players thinking, "How can I get the DM to use Lead the Attack to resolve my attack this round"; instead, it's more like "What does my character do here, given these tricks that he knows well and the current situation?"
* - This is a social level thing; for example, if you expected "slice off his armour" to be Lead the Attack, hopefully you'd ask why it didn't. Then I (as DM) would explain my reasons behind it ("Lead the Attack is not about imposing an AC penalty; you direct your allies to target an enemy and thus grant them a bonus, using your Int"), and we'd work something out. ("I picture my PC's personal version of Lead the Attack being about slicing off armour." "No problem. It might not work if the target doesn't have armour, and I don't know if it will grant bonuses to attacks that ignore armour anyways, like those vs. Will.")
I don't see this as a problem with mature players.