I have a thermostat that is currently battery powered, but could use a c-wire instead. I'd like to make the switch...

Luckily, there's an extra 5th unused wire in the cable run that could, I believe, easily become that c-wire. However, looking at the main electrical panel of our HVAC unit, there's already a wire on the C terminal; this wire runs out to the condenser unit.

My question: would adding this unused wire (wrapped, blue in the attached photo) to the C terminal in addition to the wire already there (red, running to the condenser) disrupt anything?

Thanks in advance!