
A dedicated fighter in a 4-player multiplayer game might be putting in 3-5 engages in a scenario. If you're playing Machete as your main weapon then you'll want to engage even more often, and certain campaigns are just lousy with Aloof.
For these specific circumstances, a Riot Whistle goes from being one of the worst assets in the game, to an action generating "meta-call", heck, you might just even play it as a 1-off.
P.S. Dont look at this and look at Zoey and go "Hurrr, durr, both cards have word "engage"!". These cards have pretty much no innate synergy if you're not fulfilling the prerequisites I mentioned above.