I'll agree and say it's a pain when you've got to crimp 2 thicker wires into the one terminal.
What i do is use the molex trifurcon crimp pins , you then get the 2 wires into the pin and do the first crimp.
I then apply a tiny bit of flux ( electronics grade that's non-corrosive or conductive ) and put some solder onto the crimp i've just done to hold the wires firmly in there , then i do the second crimp over the insulated parts of the wire.
I've found that if you don't put the solder on the first crimp then when you do the second crimp the wires pull out of the first.

Have patience ,take your time and you'll get it done no worries