Grey Knights were decimated banishing Angron for a time. After that the Inquisition planned to kill/lobotomize all the millions humans nearby. So yeah, whatever number of guardsmen will do, if some survive they will be killed by the Imperium either way.
This has to be a legitimate strategy in lore no? Devote a whole army to holding him in one location for an hour.
It’s been done. Whether against Angron or not, I have no idea, but the lore and attrition tactics go together like pb&j
Grey Knights were decimated banishing Angron for a time. After that the Inquisition planned to kill/lobotomize all the millions humans nearby. So yeah, whatever number of guardsmen will do, if some survive they will be killed by the Imperium either way.