End of the 2nd mission cinematic (spoilers from flashpoint)

If I recall correctly after Flashpoint,

The raiders only had 1 battlecruiser in their fleet.

The Bucephalus gave it's life to allow the Hyperion to escape Mengsk trap in Narud's labs.

So why does Valerian have 6 or 7 battlecruiser in his "fleet" in the cinematic? Where did they get that fleet?

Solution 1:

Prince Valerian is working with the Umojan Protectorate (hence the base on... Umoja).

Given that all of the units in the first two missions are either mercenaries or Umojan forces. (Instead of War Pig mercenaries, the unit, when selected, explicitly states "Umojan Marine") it seems a fair assumption that these ships and soldiers belong to the Umojans, who are working with Valerian for unknown reasons.