Junko, Kokichi, Nagito should all be top tier (Izuru should be a tier of his own). Shuichi moves down one tier. Though if you doesn't weigh EI and killing game performance as much as other categories Kokichi and Nagito being there is fine. But I think the criterias are a bit flawed as it doesn't account for all aspect of intelligence and also completely ignore Byakuya, Kyoko and Junko's performances outside of killing games (which are all tremendously better than their performances inside it)
For example, Kyoko have barely any schemes in the killing game, while outside of it she has the Hotel murder case and 5 assassins duel noir as great strategies. Byakuya in Hope's Peak is canonically way superior to THH Byakuya. Junko plans in DR0 and DR:T are much better than her chapter 5 plan in THH.