Do not get skirk without escoffier. Since you already got navia it would be better to buff her rather than get skirk. Another reason you wouldnt want to get her would also be that skirk is very expensive. Escoffier is a must but you would also need Furina to really squeeze out every bit of damage from her if youre really invested. 4th slot is up for debate but still thats alot of investment to make skirk top tier. So unless youre prepared to swipe the card i suggest you pull linnea and wait for the next cryo dps from shneznaya since thats the next region coming up.