It’s a crapshoot, there are plenty of people who go 64-0 or have 90+% records in Unlimited. Even then it’s easy to have a bad game or lose your timing a bit and start to get paranoid the sliders or setting have been changed.

There’s no real reason to try to win the Unlimited reward anyways, it’s just another card and seems to cause a lot of stress based on people’s posts. I’ve done it once and it was unintentional, as soon as I set out to actually grind for it this season it got stressful and I quit. Even apart from skill and overall based matchmaking, it’s too easy to run into someone with crazy badged out players like an AD with 35 HOF badges or something, using a Zen, or who is an elite comp player.