Whiskey’s really rough to play with, I usually recommend that people try Oscar Mike first, he fills a similar-ish role, he’s just simpler at it.
My advice is to just try as many as you can, and give them a few attempts, they never clicked for me on the first play through, some, like Boldur and Kleese actually took a lot of determination to get the hang of. Each different class (and some characters) have vastly different engagement techniques, and you never know which one is going to click for you.
Like with OM and WF you’re going to be engaging the wave first and foremost and making sure the minions are pushed back.
With shooting tanks like Montana and Isic, you’ll be zoning against enemy players and holding the front line. Supports, of course, will mostly be running around behind your front liners keeping them where they belong.
Melee assassins will be always looking for flanks, and ways to sneak up from the side or engage when they’re not seen.
Melee tanks will mostly be in the front blocking and soaking up damage.
Marquis and Toby, etc., should be dancing around in the back line adding their damage to whoever the front line is engaging.
Switching roles means you have to play in entirely different parts of the map and in entirely different ways, so you have to change your mindset, but I suggest learning at least a few different positions so you can pick around whatever your teammates are doing.