There are more concerns than weight
The vehicle in question [ a 450 with trailer & 410 E hoe ] will require a CDL/ hydraulic brake endorsement to drive. Fines for inappropriate drivers liscense $10,000. ( estimated F-450= 8000/ 410 e hoe=15000/ trailer= 7500)
To put this load on a pick-up and trailer is asking for trouble. The pick-up will wear faster and break sooner. Horsepower is a deceptive rating and a big diesel with a huge displacement will last longer and perform better.
Smaller trailers are weight rated differently than heavier trailers and come apart much easier. They have smaller axles of less width. Contact with a deer can end your business.
To pull your friends trailer, be aware that the power unit insures the trailer. If you pull his backhoe on his trailer, you become a "for hire" carrier. This requires driver files and drug screens on file and drug screens on any accident where over $4000 damage is done. ( this is an old law and may be more severe now.)
Usually a different insurance coverage is required for a "for hire" carrier and a different tag. If you pull the trailer and have an accident the insurance company will likely deny your claim if this issue has not been taken care of.
If you are certain that you wish to enter this transportation arena I would suggest you buy trailers with an eye to the future. Most grading companies are limited in their choice of grading machines by their previous choice of too small trailers. Many grading companies move all their machines except the big one because of this fact. Buy a trailer larger than you need, it will pull safer and be worth more when you're ready to move on. Buy a name brand trailer like Trail King, Fontaine, Cozad, Talbert, Eager Beaver, etc., some of the cheap ones are awful!!!!!
Grading contractors spend a significant amount of their time convincing customers to " do it the right way." I believe this is a situation where we should take our own advice. Get a competent, insured and liscensed person or company to move your equipment. The first time things go wrong, it can save your business and your life.