They can't hit Katakuri. They are slow and predictable. Katakuri effortlessly dodged boundman, even dancing around FS enhanced Snakeman's attacks.
If they get caught in Katakuri's Mochi, good look breaking out. A physical monster like Jozu couldn't break parasite. Boundman, who did, was suppressed and suffocated by Katakuri's Mochi. With Mochi's hax and lethality (suffocation) combined with Mogura's lethality, Katakuri doesn't even need to wear their durability down. Katakuri's environmental control is the cream topping.
I mean I'll wait until we see their Hybrid performances before saying Katakuri beats them combined. But individually, Katakuri is clearly stronger.