Who to raise

For new player, Anne & Mary is pretty difficult to use and their best job is to strike things real hard for a turn. You can raise her of course and there is nothing wrong using a main DPS and a second DPS if anything goes wrong. A top choice to kill a Raid Boss with massive HP, but i will prioritize a servant that have a more balanced kit and don't have any revealing weakness here.

Ushi have more stable kit and you have her at NP 5 so i suggest prioritize her first. She has a survival skill, team NP gain and team Atk up. A solid choice if you don't have a broken game-breaker Rider like Kintoki.

Bonus :
- There are Rider Ishtar on the next summer event if you lacking a durable DPS and strong AOE Rider. Very tough rider and really useful for clearing harder content and challenge.
- Rider Kintoki when Onigashima re-run is coming, a strong pick for almost every FGO player.

ordinary is pretty much right. I have Anne and Mary myself and they're pretty much niche-only in that they do very well for a single-turn busrt damage dealer. Their NP also increases in damage the less health they have so I liked putting a guts CE on them. I have Kintoki Rider now, though, so I haven't used Anne and Mary ever since.

Ushi would be a more balanced choice and can help your main DPS hit harder and build up NP faster. Having an ST NP doesn't hurt either as STs hit harder than AoE with very few exceptions like Gilgamesh.

Helena isn't half bad either since she can boost your BAQ cards for a full 3 turns (which stacks multiplicatively with Ushi's Charisma ATK buff) and can boost the NP gauge of the whole party. Her cooldowns are awful though so I wouldn't count on her for a long fight.

Anne/Mary was my first gold rider and she did well for me. But I usually viewed her np overcharge effect a bonus if her hp happened to be low rather than trying to get her not quite dead before use. However I haven't used them after getting kintoki (who has a rerun this year).