It doesn’t make sense for the Spitfire Mk.22 to have the same BR as the Mk.24.
The comparative advantage of the Spitfire Mk.24 over the P-51-H-5-NA is that it is fitted with powerful Hispano cannons, which justifies keeping its BR at 6.7. Most of the other specifications are similar to those of the P-51-H.
However, the Spitfire Mk.22 lacks the crucial ‘150-octane’ component, and furthermore, its performance is slightly inferior compared to the Mk.24. Therefore, it is questionable whether it is justified for the Mk.22 to have the same BR 6.7 as the Mk.24.
In my opinion, the ideal approach would be to lower the Spitfire Mk.22 to 6.3, as it has a comparative advantage in firepower, even though its airframe performance is slightly inferior to the P-51H.