The only concern I would have is the MMM getting hung on one coming off whatever your loaded on and moving it and sliding off. Done it before with mowers on a truck. It's not fun.
That would apply to any material the ramp was made of, wouldn't it?
Each ramp has a 2500lb capacity and you're going to be putting 1450 on each ramp. Seems that the math says it's going to be fine and you're under 2/3 capacity of each ramp. Don't know why it wouldn't work. How often are you going to be using them?
I use a pair of flat 6' aluminum ramps rated at 2500 lb per axle. I recently tried them with my JD4310 with the loader and bush hog mounted. I estimate it to be pretty much max for them and it loaded with no issues.
One thing to look out for with arched ramps is ground clearance. I bought a pair of arched ramps from TS and tried to load my racecar with them and it bottomed out on the arch.
I also have a pair of 7' arched aluminum lawn mower ramps. I think they are rated at 750 lbs per ramp. I accidentally threw those in the truck when I went to pick up an old 8N that had a loader on front and an Otis elevator gear case on the back for ballast. We ended up supporting them in the middle with concrete blocks and winched that sucker right up on the trailer without damaging the ramps.
Make sure you go over them good with a file and a pair of gloves on to clean the welding spatter. I recently tore a big gash in my hand on my aluminum ramps from a piece of welding spatter. Last time I handled them I felt another piece I missed so I need to go over them again.


They weight capacity is no problem but as others have mentioned I think you required something longer. A 7 foot arched would help a great deal in preventing MMM from hanging up on trailer and backhoe from dragging and hanging up on ground.
I bought a set of these years ago and despite being only 3000 lb capacity I've used them with my subcompact with backhoe, mower, and bucket attached a dozen or so times with no issues. The photo that accompanies the product shows my model of tractor on them so felt they'd do the trick. Also, Erickson ramps are tested at 1.5 times the advertised load capacity. You also never have anywhere that weight on the center of the ramp at any given time during loading or unloading.
NON FOLDING ARCHED ALUMINUM RAMPS – 3 LB. RATED (PER PAIR) << Erickson Manufacturing Ltd.
What are you loading on to need a 7’ ramp? I’ve never had any trailer with a ramp that long. I think I could load a small tractor in the bed of my dump truck with a 7’ ramp parked on level ground.