Ohm's Law

I looked up things about this, and here's something useful: Here.

The main equations people have used are: Amps = Voltage / Resistance (Ohms) and Power (Watts) = Voltage x Amps

I've read that people say the when the voltage is doubled the amperage is doubled also. So when you double the voltage you quadruple the power (watts). Also, slower motors have higher resistance (Ohms). See Neu's website to find these.

So how this deals with us:
A lot of people run truggies with a Neu 1515 1.5D or 1Y on 3S or 4S. I'm going to compare 1.5 (2700 kv) on 3S vs the 3D (1360kv) on 6S. These are not real world rating, just for comparison's sake. 11.1 / 0.004 = 2775 amps. And then 22.2 / 0.012 = 1850 amps.

What I've always heard around here is that when you double the voltage you want to get a motor that is about half the kv, and then it will be half the amps. But that's not how it is, the doubled voltage doubles the amps also, and the only thing that's helping keep the amps down is the higher resistance (Ohms) that slower motors have.

What I've read elsewhere is that you should get a motor that has four times the resistance if you want to double the voltage and want to keep the same amount of power (watts) and half the amps. It always seems like people who want to have higher voltage setups just multiply the kv times the voltage and match it up the rpms with the lower voltage steups and call it done, because we assume that the half kv means half the amps which doesn't seem true

I am missing something? Can some people who know about this type of stuff explain this?