The bigger issue is that Marlin thinks your extruders are actually numbered in the wrong order.

So, to fix the core issue, you want to swap the TEMP and HEATER pins on the board you're using.
Depending on the version of Marlin you're running, it will ether be in pins.h or pins_YOURBOARD.h

Find TEMP_0_PIN and TEMP_1_PIN and swap them. Do the same with HEATER_0_PIN and HEATER_1_PIN.

Or you could swap the wires.

I can do that but then it is wrong for software that uses the printer. On most dual or multi extruder software it considers the right extruder as the primary by default. Then the left is secondary and will be normally used as the support or infill extruder. I can change pins and flip wires all day long but the display graphic will still be wrong when it comes to software.

Understand I am a perfectionist of sorts and I don't just note and remember like some do. Many will note the X axis moves in reverse form the direction it should. They just live with it and remember it. Many will not they need to set a temp of 15 degrees higher because of a difference in the readings versus actual.

I fix these types of things so that they are correct and accurate according to the software functions. Left is left, right is right, up is up, and 110 is 110.

As such when I see software saying extruder 1 which is on the right says it is 110 degrees, I want the graphic on the LCD to have number 1 on the right and show 110 as well.

If I swap wires then it will be wrong from a software stand point.

So, to fix the core issue, you want to swap the TEMP and HEATER pins on the board you're using.
Depending on the version of Marlin you're running, it will ether be in pins.h or pins_YOURBOARD.h

Find TEMP_0_PIN and TEMP_1_PIN and swap them. Do the same with HEATER_0_PIN and HEATER_1_PIN.

Or you could swap the wires.

So my question is where in the firmware can I find what controls the LCD layout so I can swap those two icons.