Instead of 71 Spheroid mechs, there were actually 113
And, instead of over 15% Sphere pick rate...it was only 14.7%
Here's a list of all mechs used in the Semi Finals

I was almost surprised to see the Summoner SO dominant as a Heavy.
H2C, less surprised, but he's since been nerfed on the Live servers already.
Specific to Light mechs...I'm surprised there's so few chassis

FOUR
Only four. Lynx and Cheetah have both since been buffed, so that representation would change, but there's so few viable Light mechs, and it shows. Wolfhound held aloft by Quirks, and the Cheetah being all around useful.
Medium wise...a single Sphere chassis was found (also held by quirks)

Coming in second after the H2C-A, and more as a Light mech than a Medium
This absolute domination by the H2C would not be the same, under the current state of the game, IMO. The agility took a solid hit on it, but it would still be a solid pick. Just...not 2/3s of All mediums

Heavy wise, a single Sphere chassis as well. Taken 4 times.
...yeah
Assault class was dominated by Laser Vomit, with the SuperNova and Mad 2C being over half of all Assaults

The most diversity overall, if it's any consolation.
Typical team composition was 6 Clan and 2 Sphere mechs, but it went as high as 4C 4 S, and as low as all 8 Clam
I'm honestly astonished at the low Sphere pick rate. I hadn't realized balance got that bad.
Under 15%...and half that being a Light mech
Under 8% of the mechs were non-Light Sphere
That's just terrible. I'm not sure things would change much in the live game either
Lynx and Cheetah are still strong (and not reliant on Medium Lasers come Tuesday...RIP Sphere Lights)
Bushy has some brawl potential with quirks, but few things mid ranged
Heavies...Clam all day er day
Assault wise, the magical Mad Cat Mk2 makes the Clams reign supreme...but maybe a token Anni, if the armor adjustments are too much; or the Atlas if his agility is restored in entirety (for a brawl deck)
I just think those numbers are telling, anyhow. The "Highest Skill Tournament in Esports" almost entirely avoiding a faction...