Only train an SA on a player that, in your opinion, is already half-decent in that ability.

If a player is not that good at CKs then imo don't train CK specialist on him. Giving SAs doesn't mean sprinkling fairy dust on the player.

As with all things, be it Q or Role or SA, don't try to polish a turd.

PS. My MC without CK is much better at CKs than my MC with CK.