It is possible to see it all as one thing, with regards to dynamic EQ, transient modifiers, de-essers, filtered key compression and expansion, multiband dynamics processing.
Clearly, there are different approaches involved here, but they are all getting at the same thing, which is manipulation of frequency specific amplitudes in the time domain.
As far as static EQ, or self keyed compression, one can set an EQ to alter the dynamics, one can set a compressor to change the frequencies... To use the words of BK, this is what "seperates the men from the boys" and of course, the women from the girls.
Best Regards,
Eric