I suspect the LACMs on the mid and outer wing points are smaller due to the structural weight capability of the wing. If you want to hang bigger LACMs, you have to hang it in the inner wing and the center fuselage.
My opinion is that the “bigger” LACM is the DH-10 while the “smaller” LACMs are based on the YJ-62 or simply the YJ-62 AshM itself. With that large nose radar and FLIR/IRST, the plane is more than just a nuclear or LACM carrier, it may also have more tactical roles, including anti-shipping.
pic of the LACM DH-10 undergoing static tests. Photo was taken couple years ago. Article mentioned it will use stealth technology(RAM).
