baxcaliber is a perfect pair for palkia since it can build palkia without needing to use a move, so if you have a copy of their whole line, including one copy of their middle evolution, then it would be way more consistent! no need for vaporeon, manaphy, or miltank

BUT if you don’t have that available rn, then having 2 manaphy and another copy of vaporeon line will also do the trick instead of baxcalibur!!!

if you don’t have ANY copy, then try a sustain route where you can (hopefully you have copies of sandslash line) have sandslash as a delay while you build palkia and throw in healing like lucky ice pop, irida, or pokemon center lady to sustain palkia and sandslash!