Some people are hard to satisfy.
But this is the kind of thing Visio is good in. Even no need for custom
line patterns.
Right click, Format, Line, Section Line Ends, Begin e.g. nr 40
This is when you are satisfied with two arrows at the end.
Remark the funny, ludricous, denominations for the sizes :
Extra large, jumbo, colossal.
But I have the feeling you need custom line patterns. Not easy !
I even did not remember how to start making a custom line pattern without
the help of the help.