It feels more annoying and makes you think “I need to have this merc in my squad for the achievement” than an actual achievement.
The 30 minutes one is fine, heck even the 5 hours is not too bad. But 20 hours is just way too much and it’s just annoying.
So please, for the next mercs, don’t add a 20 hours achievement. And if you do, then add it to all mercs with a special reward. Maybe a chibi trinket of that merc, or a trinket with their gadget/ability (mini SNITCH for Aimee, mini health station for Aura, etc.). But then it needs to be an achievement for every merc and not just new ones.
tl;dr: title
Edit: Oh yeah and the “craft a cobalt” card should be removed as well. You can replace it with “obtain a silver or better” (special edition counts too) if you really want to encourage people to get a card for the new mercs, but a cobalt is ridiculous.
