TSS scores, especially in our mountain sports can be very much like comparing apples to oranges.
I strongly suggest you do not compare yourself to others. Many factors come into play: How long have you been training using TP? What is your fitness background to name just two.
Does your friend train for a conventional endurance sport like running or cycling? If so, TSS will be more easily calculated and quantified.
CTL is a better metric of work capacity but the model for calculating it is a backward looking non-linear weighted running average over the last 6 weeks. We have found that CTL is not very accurate until it has several months data to look back at. This is because when you start TP assumes you have a CTL of zero.
What we see is people who have sustained a high CTL for several weeks do better in big mountains. I once ran some numbers out there but people wanted to use these CTL levels as proxies for their preparedness for such and such climb. So, now I shy away from making too specific of recommendations. I can tell you that some of the top alpinists I coach sustain a CTL of over 130 for months on end before a major climb. Most of our amateur Everest and Denali climbers will top 100 for several weeks leading into their departure.
For Rainier which is only a couple of days long a much lower CTL can suffice if you are mentally tough and do not mind suffering. Speaking in very general terms I would say that person with a CTL of 50 is likely suffer much more than one with a CTL of 85. However, many non-fitness factors come into play. Such as the altitude and who well you do above 10,000 feet. If you are coming from sea level then it is possible that the altitude will be as big a factor as fitness.
Your CTL should be used to measure your fitness against your old self. But you must be consistent in how you calculate it.