well, first of all, scorpio is ruled by both pluto and mars
it means their influence is the strongest in the chart.
as for pluto, the sign it's in is generational. its in Sagittarius for everyone born from 1995 to 2008. dont focus on the sign too much, focus which house pluto is in for you. chart rulers hold significant influence in the chart, and the matters of houses where mars and pluto are for you should hold more importance than the sign