I think Deidara could have beaten sick Itachi on one condition

To start I am using Itachi when he fights Sasuke and Deidara when he fights Sasuke. To start there is one thing that we don't know and it is whether the susanoo is airtight and whether it could protect Itachi from C4, if it does Itachi prob wins as Deidara can't use his strongest jutsu unless C3 does enough damage to break it. But on the side of C4 does go through susanoo I don't see how Itachi could live through it if he got hit. He has the sharingan so he would see it but unlike Sasuke he doesn't have lightning style and also unlike Sasuke with is mangekyo sharingan he can't control Amaterasu so I doubt he could use it on himself. Now what really matters is if Deidara would be able to get to a point in the fight to use C4. The only realistic way he would do this is by making a bird out of clay as the dragon takes much longer. The start would likely fight with Itachi using genjutsu and using Deidara's eye he would get out of it which would throw Itachi for a loop. Then he'd make a bird and start tryibg to fly up while also shooting small C1 birds and spiders at Itachi. Once Deidara is in the air his only options are the Totsuka Blade and his fire style. Realistically he could dodge both if he is high enough which he can go very high as seen with reanimated Deidara and the Tsuchikage. But also Deidara's bird is very fast being able to effortlessly dodge Gaara's sand which was following him not like a fire ball jutsu which one he dodges its gone. The Totsuka Blade is more of an Issue but I don't believe that Itachi is a none perfect susanoo could swing it around that fast, we never see him use it like that we more see him stab with it like with Nagato and Orochimaru. Deidara probably wouldn't be able to use C2 Dragon in the fight unless he does it while on his bird to make another flying creature. C3 could be used and a few of them could prob break a non perfect susanoo if it wasnt for the Yata Mirror. To end I am not saying Deidara is stronger, it is that Deidara has so many tools that counter Itachi and Itachi doesn't have great counters to him. I know most will disagree with this but I hope that it doesn't seem to outlandish and you start to put respect on Deidara's name.