I love the idea, but also agree with RJ that you should weigh the tongue and see what you are working with in terms of tongue weight first. If you plan to store the generators there, you can secure them with cables and locks like this Master Python I used on my Honda 2000:

Two issues I had were keeping the generator safe from weather...I had the Honda fabric cover that was water resistant but still let the gen get wet in the rain, plus you can't run it with the cover on. Second issue was the vibration in the trailer when running the gen on the rack.
Again, I think that rack is pretty cool, but it creates some potential issues.
I removed my rack and added a rear storage box where the gen stays inside and safe from the weather. Click pic for build thread:
This size box will easily hold 2 2000 generators.

When I run it, I take it out of the box and set it on the ground underneath. I still use the python lock to secure it to the TT frame and having the box above it keeps it dry from the rain.
Be aware that this mod will have the opposite effect on your tongue weight and can reduce it significantly.