The fight wouldn't be so cut and dry. Samehameda is a factor here since it can cut chakra and absorb it. If its made of chakra it can cut it and absorb it. As far as I know amaterasu is made of chakra so its susceptible to being absorbed. Kakashi already experienced tsukuyomi once so its not likely he would fall under it again. Going based off their last fight kakashi out smarted him with the clone which left him open to naruto's attack. Granted he couldn't use ms but smarts has nothing to do with ms and in this instance he out smarted him. Even during their first fight he countered his jutsu and only fell to his eye technique because he thought it was a regular genjutsu(notice he closed his non-sharingan eye and resisted it a little, to which itachi complements him). The exploding clone was not his fault and rather he took the damage to save kurenai. A fight between itachi and kashi would be a tough one. They are both at the same level. Kisame vs itachi is also another tough close match and adding another ninja of the same or near the same level increases the chance of the duo beating him. You have to look beyond the jutsu, at this point naruto has beaten some of the most powerful ninja in the world with the same moves. Its not the number of jutsu or their power its the way you use what you have. MS jutsu require huge amounts of chakra and if there is any indicator itachi would literally have to hope he hits them within his limit. Kamiu is a problem, samehameda is a problem. Kisames final water bomb absorbs chakra and with that said anything chakra based would be destroyed by it. Thats why he was surprised he lost to guy because he thought his jutsu was chakra based. I'd say kakashi and kisame would win, itachi is good but not good enough to take on two ninja who are also at his level at the same time(especially since one can counter his chakra based moves and the other weilds space time jutsu capable of teleportation).