The Gorosei have strong abilities and hax but they have poor skills as combatants, expected of characters who do have such hax anyway. They’re a line of defense who storm a place as one squad and work as a unit to achieve a goal.
Maybe they were never meant to be compared to normal top tiers
If their hax stand, then normal top tiers can’t put them down
However, the Gorosei can never really put down a skilled fighter, I can only see Meme losing to a Gorosei due to how sloppy she is
We cant judge if they are bad fighters because non of them actually did any fighting.
Pumba has only been in his Zoan form charging people down.
Mars in his Zoan form firing his blast.
Ju Peter literally didnt fight shit lol.
Saturn doing mostly nothing except for when he fought the straw hats and then he forgot he can freeze people and explode their heads, even then he was mostly in his head talking to the other Gorosei about what to do with the broadcast and when hes had enough of the straw hats he blew them away and Robin had to catch them.
Only Ghandi really displayed some combat skill by blocking Zoro and clashing with him but thats about the extent of it.
Its too soon to say they are bad fighters lol.