Why isn't Jiren Low 1-C?

[Hellformer]

So basically we know Shin stated that Jiren had power greater than anyone they've faced off against before, including the likes of Fusion Zamasu in his corrupted state. And we accept fusion zamasu's power to be eventually Low 1-C so why does Jiren cap at 2-C?

 

[Thelastmlg]

Because he never reached that level, shin compares jiren's power to anyone they faced before, but they never faced the low 1-C zamasu, it was a impeding outcome that got stopped when zeno erased him

So basically they never experienced the low 1-C zamasu's power to compare it to jiren