I believe not. Usually the HOG systems themselves are developed concurrently for both locomotives and coaches after a standard is defined for HOG. And also there is nothing inherently HOG or non-HOG about the rake (Except probably for the option to switch between EOG and HOG). Electrically, they can always a develop a HOG system for the locomotive that is compatible with whatever connections are available in the coaches. In our case, the problem came up because of our Jugaad way of doing things. The WAP5/WAG9 design was independently developed and did not factor in any of the design specifications of the LHB coaches. So they had to come up with a way to make both of them compatible for HOG.
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more... And at that time IR itself had not finalized any spec for a HOG system. A simple (but ingenious I'd say) system was developed for a bunch of WAM4 and WAP1 locomotives that was soon abandoned as the focus shifted to 3 phase locos.
A better example of HOG system is visible in the west. Many trains (even those with diesel locomotives) don't run with separate power cars. The loco itself houses the entire system and just powers the coaches directly without requiring an intermediate power car. The WAM4 and WAP1 designs too did the same earlier, until they were superseded by the EOG based later design.