While it is easy to keep this discussion going, we are starting to digress from the core purpose here.
Look at it this way - the question we are trying to answer in the context of this discussion is - What is the probability of HDFC AMC further being hit by regulatory moves?
In my opinion the probability is medium to high whereas in your book it might be low to medium. I think HDFC AMC will get both by SEBI (due to further action on expense ratios at a later point of time) and RBI (if they direct banks to move all third party product business out of the branch infra into a separate entity which will be regulated as an advisory entity) while you may accord a much lower probability to that scenario.
The key point in investing is to think of all scenarios, estimate probabilities and buffer for that. So let’s estimate our probabilities, quantify the impact to the extent possible and and move on