The answer to your question lies in the subtle difference between eg a x00 tick chart and eg a y minute chart which superficially look similar, but are not when getting down to the actual trading.
I recommend trying this out over a period of time and seeing what happens, if anything to your personal results.
But for longer time frames, the activity vs time issue is covered in Richard Arms's book about volume adjusted width price bars, whereby eg a high volume bar widens into a box, that is, it has more x axis allocated to that bar.
Volume = activity = momentum = open interest change=breadth, broadly speaking, but each has it's nuance and specialist inherent advantage. P&F is the activity variant.
I hope this helps clarify.