There are apparently distinctions in dying from and dying of that I either don't observe or am unconscious of observing, but that I can't explain.
I'm sure there are people somewhere who would say that it matters which form of "drowning" you use, but I can't say that it does.
I don't find the "bludgeoning" to be very natural. Being bludgeoned, perhaps, but it's simply not a word I use frequently.
Note that drowning can be (and usually is) accidental, while strangulation is usually through the actions of another (although accidental strangulation is possible), and being bludgeoned to death clearly implies murder. Were you thinking only about murder when you wrote this?