What should the consistency of the meat filling of moussaka be like?

I intend on cooking a lamb moussaka (having never eaten one before); in planning to do this I've referred to numerous recipes. The meat filling of the moussaka seems to be it's most integral element however in looking at all these recipes I've been unable to reach any consensus as to how this should be cooked. The sticking point seems to be the choice of ingredients to cook the meat filling with. My options seem to be:

1. tomato passata/canned tomatoes/peeled


2. tomato puree


3. or a combination of both.

I am under the impression that the meat filling in a moussaka tends to be less tomatoey and thinner than say a Ragu alla Bolognese meat sauce. When cooking a Ragu alla Bolognese meat sauce you're aiming for a nice thick consistency with caramelisation of the tomatoes in the sauce.

I feel that cooking moussaka meat filling with tomato passata/canned tomatoes will result in the meat sauce being similar to that of a Ragu alla Bolognese. Is this desirable for moussaka?

Can someone guide me as to the consistency I should be striving for?