Yes, it is a common area that is poorly done by most as they have no training in the area and most of the DIY kits Like PAINFUL do not address things like USING THE PROPER CRIMPERS and TERMINALS.
HMM Problem: I don't have the correct sized terminal SOLUTION: Strip extra insulation and fold wire multiple times as needed
OR,
Wire(s) are to big for terminal SOLUTION: Cut as many strands as needed until it fits. THE PRO's know to cut the same number of strands off each wire when shoving multiple wires in to a TOO small terminal LMAO