300ma vs 1400ma where? for your battery pack?
300ma is probably about what the servos will draw siting idle, so if all you want to do is sit idle and mot move it should work fine for you.
Voltage and current need to be what they need to be to operate properly. The voltage need to be 4.8 to 6.0vdc for most servos. If the voltage is too low it will not work. You can never have too much current. A servo’s current demand is proportional to the amount of work it’s doing. Little work - little current, lots of work - lots of current. If you provide little current and try to do lots of work the voltage will drop. It’s a mathematical rule.
When I saw the wheel, I wanted to spin it for a prize. Then I realized it’s Ohm’s law. 