You can see on the sensor below that there are two inputs. One is for a gauge one is for a warning light. So it is doing two different jobs in one sensor. The warning light part is a simple switch, in this case it will switch at 98C + or - 3C. When the switch is open the light is on.
The other pole is for the gauge and dose a different job. This pole senses temp and gives a known resistance depending on temperature.
This resistance is what your gauges are measuring.
So do you connect one gauge to each tab - no.
Will two gauges work off a single sensor? Yes should do in the worst case you can use a switch-over relay at the fly bridge for when you are up there.