In terms of having a complete skill/ability set that has no bad matchups.
It would make sense of why they were portrayed/stated to exist in their own matchup grouping separate from others, based on the "only a Sannin can beat a Sannin" statement. It could only work if there were no weaknesses for weaker characters to exploit. In that way the only thing that would matter in fighting one is if the opponent is at a high enough level to beat them.
Now their skills can obviously be broken down to disprove the idea of them having no particular weakness, but do you think they were made to have no weaknesses, by intention?
It would make sense of why they were portrayed/stated to exist in their own matchup grouping separate from others, based on the "only a Sannin can beat a Sannin" statement. It could only work if there were no weaknesses for weaker characters to exploit. In that way the only thing that would matter in fighting one is if the opponent is at a high enough level to beat them.
Now their skills can obviously be broken down to disprove the idea of them having no particular weakness, but do you think they were made to have no weaknesses, by intention?