Perché dovrebbero venire uguali se i codici sono diversi? Dove hai preso quei valori?
E come intendi fare per la punta della freccia?
Comunque, la versione “tagliata di netto” è questa:
`\makeatletter
\pgfarrowsdeclare{left stealth}{left stealth}
{
\pgfutil@tempdima=0.28pt%
\pgfutil@tempdimb=\pgflinewidth%
\ifdim\pgfinnerlinewidth>0pt%
\pgfmathsetlength\pgfutil@tempdimb{.6\pgflinewidth-.4*\pgfinnerlinewidth}%
\fi%
\advance\pgfutil@tempdima by.3\pgfutil@tempdimb%
\pgfarrowsleftextend{+-3\pgfutil@tempdima}
\pgfarrowsrightextend{+5\pgfutil@tempdima}
}
{
\pgfutil@tempdima=0.28pt%
\pgfutil@tempdimb=\pgflinewidth%
\ifdim\pgfinnerlinewidth>0pt%
\pgfmathsetlength\pgfutil@tempdimb{.6\pgflinewidth-.4*\pgfinnerlinewidth}%
\fi%
\advance\pgfutil@tempdima by.3\pgfutil@tempdimb%
\pgfmathsetlength\pgfutil@tempdimb{5\pgfutil@tempdima-\pgflinewidth}
\pgfpathmoveto{\pgfqpoint{5\pgfutil@tempdima}{0pt}}
\pgfpathlineto{\pgfqpoint{-3\pgfutil@tempdima}{4\pgfutil@tempdima}}
\pgfpathlineto{\pgfpointorigin}
\pgfpathlineto{\pgfqpoint{0pt}{-.5\pgflinewidth}}
\pgfpathlineto{\pgfqpoint{\pgfutil@tempdimb}{-.5\pgflinewidth}}
\pgfusepathqfill
}
\makeatother`
Ciao