I went through all this about 2 to three years ago, 1 ton GMC Diesel and a 15000 pound fiver, I needed a AR licence to be legal.
I did all this and had a AR licence, but since I'm over 65, MOT wanted me to do another medical and the whole test all over again (every birthday), they down grated my licence to a D now.
The Ontario Trailer ass. Now has an agreement with MOT, that after doing a test at your dealer, they will send you an additional licence, making it legal to drive a trailer with a G licence for you personal use only.
If one delivers trailers for a living, you still need a AR licence.
Same test then an 18 wheeler, except you don't need the air breaks.
Hope this helps, nobody will stop you, except should one have crash, then one might be in trouble with a plain G licence.