Other bit that's different between 1.2 / 1.5 descr_strat is that 1.5 has
superfaction romans_senate
line under for each roman faction (julii, scipii, brutii), i.e.
faction romans_scipii, bureaucrat napoleon
superfaction romans_senate
denari 5000
etc..

putting that in might make senate tab workable...

However there are some modding solutions (generally for removing senate) which require you to remember not to click senate tab / offices - don't know if this is one of them!