Crit support for Anne & Mary Rider

Of these Marie caster would be the strongest support, but even then she's beaten out by Hand Christian Anderson as crit support.

Hans with 2030 is great, if you don't have him, caster Liz has the best stars per turn - 12 on a 5-turn cooldown, though unfortunately she isn't really good for much else. Helena has the least stars per turn - 5, but it lasts for 5 turns rather than 3 and has an 8-turn cooldown, and she also has other buffs too. Marie is kinda in between - she gets 10 per turn for 3 turns on a 7 turn cooldown, which means she has the most dead turns, but she also gives an attack buff and is pretty tanky.

Summary: For most stars consistently, caster Liz and 2 2030. For varied buffs and least stars, Helena, and for a middle ground Marie.

You want the absolute best star gen support? Go borrow a saber Lancelot. The amount of stars he crap out a turn is mind blowing. Then use Hans with 2030 to further supplement the stars as well as additional crit damage

Congratz for the 2x 2030 CE, you can try x3 2030 CE for funs.
For the core supp of your crit team i must say it's Hans, no need for further explanation because people mostly know about his quality.

For more Crit damage and less star, Caesar. He also has lots of steroid, similiar to Helena but with a low skill CD.

Marie Caster is really crit supp good for your DPS, as she is a solid available crit supp on your roster. More Stable at a fight that need consistent damaging and a bit staying power.

Helena is for shorter fight that needed strong burst and to OHKO some enemy in a few turn. I own her on my team. Pretty much i don't use her on a longer fight but still it depends on the enemy/bosses.

What Crit supp do you need ? Is it crit star oriented only servant ? Is it the Crit damage one ? is it the combination of both, but with a Fifty-Fifty effect ? is it crit supp for harder content ?
is it Crit burst damage supp or glass cannon crit style ?

There is so many conditions to use that supp as they're great at their role.
My advice is raise them based on your needs, but if i would choose Hans is your man then Marie as your next main supp.

Though, the next decision is in your hands.

I'm gonna second most of the other people here and say that you should go with Hans, instead of the other supports that you mentioned. He boosts crit damage, attack power, star drop rate, and defense, as well as gives stars passively and regenerates your health. None of those other servants that you mentioned can even come close.

Of course, you could always use Hans *and* one of those other servants together, in which case I'd probably go with Marie or Helena.