Sneaky AI shouldn't be so blunt, and is ill-prepared

AI will sometimes give a message while the player is at war with another faction, essentially stating something to the effect of "You're at war with someone else, so we're going to attack you now while you're distracted", but will not actually declare war or begin attacking, or seem actually prepared for hostilities (no mass gathering of fleets on the player's borders, or within the AI's systems). There are a few problems with this as implemented-

• Immersion-
  • The AI is meant to be a sovereign of an empire on par with the player; why bother with such a clunky explanation for attacking the player? Simpler/more elegant language would be preferred, maybe even based on the faction leader. For instance, Unfallen could say "The fire burns in your empire, we shall renew your people", Cravers could be most blunt "We hunger for such easy pickings"
  • The AI does not immediately declare war, and may not ever declare war, making the statement itself lose all meaning.
• Gameplay-
  • The "sneaky"/"opportunistic" AI has now declared their intentions openly without immediately striking, eliminating the element of surprise by giving the player several turns to build or move fleets, broker peace in current conflicts, and/or force peace with the sneaky AI.
  • The "sneaky"/"opportunistic" AI rarely seems to have its forces gathered in a posture prepared for hostilities, so even if war were declared immediately they are not actually prepared for their own surprise attacks.

A declaration of "we see some weakness/distraction in you, so we're attacking now" should be accompanied with an immediate declaration of war and actual hostilities from the AI.

Edit:

I just recently played a match discovering another thing to add in here. I was allies with a Lumeris AI and at some point they gave a message basically stating that in some way they were backstabbing me, and their relationship changed to "deceitful". I immediately sent fleets to "defend" all of their systems and haven't seen an issue since from my now "loyal" ally.