Therefore my reasoning is this.

it’s true to say that 20% of 500 votes is 100 votes

… and that the difference of 200 and 300 is 100

… and in respect to a total of 500 votes (not 300 or 200) there is 20% difference between the two based on total available votes because 20% of 500 is 100.

It’s true to say that 300 is 60% of 500 votes and that 200 is 40% of 500 votes.

It’s true to say that 200 * 20% = 240

It’s true to say that 200 * 50% = 300

It’s true to say in this example that 300 votes versus 200 votes means that 300 votes is 50% more than 200 votes.

Mathematically these are all correct (I hope!!!) lol. The difference in votes between the two based on a total of 500 votes would be 20%. But 300 is still 50% more than 200 votes.

Cheers