[SmG Phoenix]

Goku and krillin were both moving faster than the speed of sound when they were like 7 lmao. Anyways if talking about strongest anime character its Goku but in a 1v1 can't say. Superman is still stronger than any anime trash tho.

Yes, but no one in the DBZ universe can approach the speed of light. For Saitama to generate that many clones requires something much faster than speed of sound.
And of course Superman could destroy most people in the manga/animeverse because they are based around different types of plots. Superman's story does however share similarities between itself and One-Punch man's being 'the god amongst insects'.
So from the current comics, even the unperfected storyline, both Saitama and Superman share the trait of: 'the protaganist only needs to be as strong as he needs to be'
Both are limitless in power, for Saitama so far anyway. Like I said, until someone nominates a character who is similarly limitless in power, there isn't much to assume.