Thank you for your feedback.

So, using your and elbigelow’s advice, what about something like this:

“A dinosaur army is conquering the Holy Roman Empire and only Charlemagne’s handpicked elite troop The Scara stands in their way.”

I dropped the year/epoch, Charlemagne should be enough indication of the historical setting.
Also, I could use more species of dinosaurs, I only had some breed of Utahraptor in mind, so far, but why not a second one?

While the business magnate is the main force behind the whole event, without more information she does not add anything to the logline.
Maybe like that:

“Charlemagne’s elite squad The Scara have protected the Holy Roman Empire for years, but can they defeat an army of dinosaurs, lead by the richest woman in the world – who pulls some of the Scara to her side?”

That some of the Scara yield to the temptation of power is an important plotpoint – still, I’d like to do better…