Are there any good ideas for stopping Roman standards from snapping off after a while?

I would even go so far as to suggest that maybe a slight change to the mould would be a good idea: make it so the standard is actually close to the bearer's face, so it can be cast as one rather than in such (admirable but) fragile detail.

Is it possible to replace the standard pole with a pin?  I've had problems with Napoleonic flags that droop or get snapped off, so use a pin (Hobbycraft 0.5mm) as the pole, cutting off the original pole and drilling out the hands.  The replacement poles will stand any amount of rough play!  It is probably easier for me as I get a nice flag to distract the eye.

The thing with Roman standards is that they're not flags. They are a lot shorter and they have several emblems on them. See example. Meanwhile I've resorted to glueing them to the standarbearer's face! That seems to work.

6 mm could not live without Superglue... and I mean it!... specially if you indulge in conversions as some fools like me indulge on... alejo dorca

Indeed, especially the gel kind. I've used that more than once to prop up men who had broken both their legs! Of course they will have to go in one of the middle ranks so you don't see their globby prostetics, but that's OK.

Great picture - looks like a good solution to me (not really a Roman expert).  The side of the head/helmet/shako is a pretty good anchor point for flags/standards/spears, or so I've found !