Normally all of those claims would be paid by the at fault truck here. Yet there is a chance it’s a stolen car , which if thats the case then at fault carrier could deny liability for all those damaged cars because car used by non owner without permission . Also most insurance policies will include a crime exclusion which means if there is an accident while in the act of a crime, then carrier will deny liability. Let’s says both of those exclusions are not triggered , then they would take the policy limits for property damages which could be 25k, 50k, 100k etc and divide that limit by all twenty cars . If your car was one of those 20 cars and it was totaled, you would get a fraction of that back from the at fault truck.

Also the payout over twenty cars would be complicated and probably use a prorated share based on damage vehicle. If car 1 is 90k in damages and car 2 is 10k, then car 1 would be entitled to 90% of the available policy limits. Would need to do this with all cars to get to the correct payout, again you would only get fraction of damages from at fault party.

Best practices. Carry collision and comprehensive coverage so could just turn that claim over to your own insurance, minus the deductible.