The placement of the capacitor on the tone pot basically boils down to the builders choice on what would be the strongest mechanical position for the capacitor.
So long as the tone pot and the tone capacitor form a series chain from the signal at the volume pot to ground (or Earth as some call it), and the correct two points on the tone pot are used, then it is all good....There is nil electrical difference if the capacitor or the tone pot is first in the chain.
The electrons don't care if they visit the capacitor or the tone pot firsts, it is the interaction between the cap and pot that is important. The value of the resistance of the pot (where the shaft rotation is set to at that time) and the value of the capacitor form a type of series filter that allows the higher frequencies to pass through. Change the value of either and we change how the filter works, and thus the frequencies and the amount of those frequencies that are permitted to pass through the filter to ground within the guitar instead of out the output jack to your amplifier.
Hope this helps.