Sorry for the late reply... I just went on a SSB4 binge and my eyes are sort of glazed over. Anyway, I say that you should play whoever you want and whoever you like. Sure, if you're looking to have a good chance at competitions, pick the higher tiers, but pick someone from there who appeals to you. Regardless of tiers, I don't like Diddy at all and it's probably because of the Subspace Emissary forcing you to use him and how the stocks worked. Play as Ganondorf, Dr. Mario, Lucina, Link, Zelda, Marth, Ike, Peach, Rosalina, whoever. Just play someone who you like and who just feels right with you play style.
I'm a Falco main by choice and because I like the challenge of playing as him and showing that he isn't trash despite his lack of (godplayer) zoning and an incredibly fast meteor. Ike remains character who I'll use for match ups I'm not familiar with and I need someone who's familiar, but also powerful and Ganondorf remains the funniest character because of his ability to boot people across the stage. For other characters, Pit's the jack of all trades and I can use him whenever I want, Yoshi's Yoshi, and Luigi's Luigi. It's just a wide variety of people to play with for the sake of messing around. Here's the thing, if Wolf was ever released for DLC, I would probably secondary him alongside Ike and Ganondorf. I just love how visceral his move set is.
So, do what makes you happy and what doesn't frustrate you. I'll be damned if I say that Falco doesn't frustrate me. His air speed, Up Smash hitbox issues, Blaster end lag, and Falco Phantasm missing about half of its hitbox annoys me. There are times I feel like if I was using Ike or even Ganondorf, I would be hitting, but Falco just can't catch up to follow up much. Hell, people have started to notice his go-to combo setup of D-throw to Dash Attack doesn't even true combo with a lot of the other characters.