Consolidating Transports

Guys,

we have about 200 Workbench & Customizing transports. i want to consolidate the Workbench into one & Customizing into one transport.

so i will end-up with 2 transports.

is this possible ??? i tried it with a few... but it didnt work... although individually importing them worked... when i created a consolidated on using about 10 transports, the consolidated one failed.