Synergies and Strategies for MHXA?

I assume the servants you have listed are the ones you have?
MHXA don't have real issues generate her own NP, but if you can give her more, she is more than welcome. She don't have hard defence or survival skill (especially she takes extra damage because of berserker) so servants that gives her guts, evade or invincible is good for her

Apart from the infamous Skadi, I guess other servants such as Irisviel, Jalter (double attack buff because dragon trait), Umu bride, Hans, Waver is good.

MXHA does have heal up in her first skill, so servants with heal helps her to stay alive too

Edit:just to add, since she deals extra damage against sabers, so she is also good to pair up with bunch of archers, so the likes of Tristan, David should be good too

Ideally, like most Berserkers, MHXA requires tank support. Mash, Georgios, and Leonidas are good tanks with a taunt skill that can take the heat off of her. The sad fact is, none of the servants you listed synergize particularly well with her, except Jack.

I think your ideal comp is MHXA, Jack, Mash. Hit Mash with the Star Gather rate down skill if you need it to give either Jack or MHXA more stars. Until Skadi arrives, MHXA is a very lackluster servant with very few support options.

Right now MHXA works pretty well as a stargenner, because while she doesn't generate as many stars as Jack, she also doesn't take up as many either, and her third skill lets her turn someone's star weight to zero. Pairing her with Someone like Rhyme, or any Lancer/Avenger helps guarantee the stars go where they need to, despite those classes low star weights.

Recently her work isnt that great since like you mentioned, (1) No Skadi to help her and (2) Her 2nd skill isnt buffed therefore her ability to finish a battle soon is questionable, otherwise berserker's durability became a critical issue if you cannot finish a battle soon

This is my idea for pair her with Jack and one Caster support (especially for caster with turn-based healing like Merlin/Hans, or Medea Lily/Irisvile).
in this case, Jack's 3rd skill could be excellent to extend MHXA's survivability, as well as additional caster's healing (Particularly NP2-5 Merlin). Meanwhile, because MHXA's 3rd skill isn't that reliable as straightforward star absorption (like Raikou), you still need other team member to provide enough star for MHXA's critical damage, therefore Jack and Merlin/Hans are highly recommended.
So if MHXA's 3rd skill not triggered, Jack will be the major DPS to do NP spam as well as generate tons of stars. Once you capture a good chance for MHX's critical brave chain, activate her 3rd skill, and put Merlin's Buff to her, then enemy will gg. She has 2 Buster card so Merlin's 3rd skill is still excellent for her no matter Buster buff, one turn critical damage, or even healing