We currently don't have enough info supporting the Chieftain 5 and 10 getting the blade.
This report was rejected by the developers as the 2-3 photos are considered insufficient. Detailed references that confirm the compatibility:
Similarly, the developers currently dont have sufficent info to show the Type 74 G should get the blade as there is documentation that mentions it, but no photographic evidence to support it:
More detailed and backed up information is required in both cases.
Dozer blades have not been added yet to all tanks in game that can currently have them. Its already known and planned for Challenger 2 to receive a blade in a future update.
Almost all of the Russian vehicles that received a blade had them already on their 3D model as they were part of the tank. Most NATO vehicles require a brand new 3D element to be added.