IMHO, yer gonna have some trouble.
I understand that some of the states that do allow double towing, it is only behind a 5th wheel. A trailer behind a bumper pull trailer is going to really aggravate sway.
Any weight added to the trailer bumper is gonna take weight off of the tongue. I figure on my setup, I loose 15 lbs. of tongue weight for every 40 lbs. of bumper weight.
Chap , DW Joy, and Fur Baby Sango
2006 Ford F150 Super Cab 4x4
2008 Surveyor 263