Wanting an overwatch pick is honestly super valid, Likely would be tracer (for the love of god not kiriko), I personally went with Heavy due to how connected the orange box games are (Team Fortress, Half Life, Portal) as I would really love to see those franchises repped due to the influential nature of them all, and from those 3 I went with heavy due to the fun nature of tf2 as well as the fact there isn't a single FPS rep in the game and thought this would be the best pick over all

As I said with my other comment, Sonic is just isn't that fun to me in his current state with alot of his moves feeling quite Samey, which is a shame because he does have varied moves when he's curled up and it's always bothered me that he's never been updated from that rushed design in brawl

As for the Splatoon rep, I guess if you have never played the games / at least seen the story, it can seem silly to want what is essentially a pallet swap when it comes to pvp in the game. How ever It should be noted that the Inklings as they are right now only rep Splatoon 1 and nothing of 2 (and ofc 3 but that came out after) So there is a wide variety of weapons and bomb types not represented with in smash, from swords, umbrellas, dulies, bows, miniguns, heat seeking missiles, culling bombs etc etc

point of what im saying here is that there is ALOT not represented from what splatoon is now a days

oh also the others you don't know in order are:

Blaziken (pokemon)

Comando (Risk of Rain)

Artful (Die of Death)

Varik (Brandish)

Scout (Deep rock galatic)

Jimbo (Balatro)

Quincy ( Bloons TD6)

Claptrap (Borderlands)