These missions are designed to get players stuck, in my opinion. They probably intend it to be rng base so it will not be done easily.

Lucky for me, and other players who have finished stage 20 or 21 faction crypts long time ago, and those who are saving glyphs like I do, these missions are easy. Done it in few minutes after getting the mission.

What I don't like with these glyph missions is, this is a problem for new or new-er players. This will give them a conundrum (if that is the right word) whether they will use their 5 and 6 star glyphs to improve the stats of their champions or just save all of them for these missions. If they use the glyphs, it will greatly improve the stats of their champions but will delay them in these missions. If they don't use these glyphs, they are most likely slowing their progression in the game. 

When these missions came out, I already have my core team for all content so I have like total of 800+ glyphs lying around for these missions.

I was also a fairly good glyph hoarder, because I didn't want to use good glyphs on bad or average gear.  I recommend to my clan to save all 5/6 glyphs other than speed until they reach these missions.  And to still only use the speed glyphs on really good gear.  So I only got "stuck" for a bit on the last of the 40 glyph missions.  All that said unless you have all the Gomlok frags and are in G1 for tag you really are not being held back in progress.

I guess I'm just a wastrel then, I know these are end game and not meant to be easy, but there is a difference between hard and chance - it's not hard getting glyphs but the rng makes it a lottery which isn't skill based at all.  I'm S3 tag so no good there lol

Save up til CvC, they are actually decent points.  The silver sink though for FAIL FAIL FAIL sucks lol.  The rng is what it is....but most of the missions aren't skill based lol.  Use 200 DT keys, spend xxx gold bars, .... There are maybe 10 true milestone missions, rest are a mix of time sucks (especially if you don't plan ahead) and easy collects for free sheet (see if Harby edits my "swear" again).