Several parsers at once

Hello

I have searched through documentation and... well everything, but I
still haven't found what I'm looking for. What I'm wondering is: is
there a way to have multiple parsers working in the same project?

Say in a project I have Cobol files (.cbl), C files (.h.c) and Shell
files (.sh). What I would like to do is use global's own parser for the
C files, so that I can have "find references" functionality. But I would
like to use universal-ctags for the cobol and shell files (since global
doesn't support those natively). Is this possible?

In almost all the examples of a gtags.conf I have found online, you have
to choose _either_ 'native' or 'universal-ctags'. I would like to have
both at the same time, and which one to use decided on a file by file
basis by the file ending.

In this example:
https://github.com/yoshizow/global-pygments-plugin/blob/master/sample.globalrc

'default' is both 'native' and 'pygments'. Does this mean both are used,
or does this line:

:gtags_parser=C\:/usr/local/lib/gtags/pygments-parser.la:\

mean that only the pygments-parser is used, even for the c files?

Regards,
Joakim