A few things I have learned working at a dealer.
Combines are a fire hazard especially if not kept clean. An exhaust leak, a bad bearing, Mr. Squeaky gnawing on wires are good fire starters.
Electrical fire can cause more damage than what is visible. A short can cause the starter to operate, this may draw burnt hoses and other things into the engine. They can also cause other component damage from misdirected voltage. Until the battery is disconnected or the main cable shorts to ground and kills the battery you have wires that are shorting and causing more damage.
Insurance -- Usually good to have. Always found it a must on a financed unit Will not pay all the damage. One job the agent said "we will deduct 10% for betterment". What?? "the parts you are replacing are old the new parts are new so they are better" Still?????
Warranty -- Warranty covers DEFECTS in Material and Workmanship. Not wear parts, not abused parts, not wrecks. Had a fire job that was warranty and they replaced all parts EXCEPT the part that caused the fire.
When you think you have all the parts for the repair, double check you will find you need more.
Had a combine that burned. repaired it enough to start the engine to be sure all was good--- Kept getting sprayed with oil, found the fire had melted a tiny hole in the aluminum valve cover. Aluminum parts disappear quickly in a fire!! Damage to wiring harnesses can go a lot farther than just where the fire burned.
I would badger the dealer and or the company and would not take delivery of that new tractor, it is a good wedge to get some action on the burned unit. And determine what started the fire. If the fault is the manufacturer you should not have to pay.
Good luck hope you can get that repaired and have little if any out lay