I use:
PM to ingest, rename files and carry out initial edit to cull out obvious bad images, then,
Fast Raw Viewer (opened from PM) for a technical evaluation of the images, and further culling then,
PM again to keyword, rate etc., and more detailed image assessment, then send "copies" of raw files to...
Capture One session, for raw processing and initial editing and further culling, images that don't make the grade are deleted in C1, others are fully edited in C1, or round tripped to...
Photoshop for important images, then
Capture One again to prepare output file (put into C1 session output folder), and final editing, colour grading etc, and back to..
PM for final captioning and keywording, depending where the file is going.
Neofinder to catalogue the original raw files and the C1 sessions.
Seems very convoluted when written down, but each program offers something that others don't. It's a bit iterative and not all steps are needed with every image, but master control of metadata is Photo Mechanic, and I make good use of templates, autocorrect and code replacement in PM.
Cheers,
Graham