@Jbennett - Unlike Acnologia, who simply powerscales above FDK Natsu (without even having fought him), Doflamingo scales to Jozu and Aokiji and being vastly superior to all of the known Vice Admirals of the marines (except for Otsuru and Garp, who are supposedly Sengoku's equals).
Even though Doflamingo was injured, Base Luffy was capable of applying superficial injury to him with singular punches and kicks, giving him Small Island+ Attack Potency. Luffy was also capable of shoving Fujitora back with Gear 3rd punches and kicks, and managed to withstand Ferocious Tiger, which is a Small Island attack, further supporting his AP and Durability in base.
With Gear 4th, he was brutalizing Doflamingo, causing clear damage even if Doflamingo managed to mitigate the impact via blocking with his arms and haki. He was later one-shot by King Kong Gun, albeit both being at the very least moderately fatigued from their fights.
You see, Doflamingo and Luffy are both scaling to eachother, and to Island level or even higher characters. I'm not saying they are Top tier, but they are not fodder to someone like and old Whitebeard or Akainu. If they are even 10% as strong as someone like Aokiji, they'd still be Island level.
Also, Fujitora is not yet proven to be on the same level as Kizaru or Akainu, but due to his lifting feat and scaling to Akainu, he is currently "At least Island level" until further notice.
By the way... you should refer to this if you want to argue that Acnologia is Island level for "busting Tenrou Island":
https://vsbattles.fandom.com/wiki/User_blog:Lina_Shields/Mountain_level_and_Island_level - we had a massive discussion about this and destroying an island doesn't automatically make you island level.
@PaChi2 - Crocodile actually got upgraded to Small Island level due to being capable of not being fodderized by Doflamingo, Jozu, Akainu and Mihawk... all 3 of them are at least 6-C in tier. He tanked a punch from Jozu, deflected a blow from Mihawk, fought Doflamingo off-panel for some time, and managed to be relevant in the fight between Akainu and the WB commanders without being killed.
It isn't enough to suggest he is Island level himself, but i do find it to be a plot hole that he got beaten by Alabasta Luffy and here he comes deflecting attacks from Island+ level characters. I'm wondering if he was given a punching bag in prison to train XD kidding of course.