well before 1.4 it wasnt worth it most of the time for a sorc to use oil in a big group, streaking in order to negate was more valuable. now the only change is streak is too much magicka for the little ult its going to generate so all sorcs will be doing is oil poting and operating siege in the middle of fights to get enough ult to negate then repeat.

imo just rename sorc to engineer and give them +15% speed when operating siege, fixed ur game for you zos np