Is that your cat in the picture? He seems like he does have an interest in the hamsters, so it's good that you have lids.
It's good that you actually listened and got a new cage! I would love to see the set up.
The picture of the living world green eco habitat shows the set up, and I'd recommend putting back the castles and all that in the left side of the picture where there is barely anything and it's very open.
Hamsters feel more safe when they have more things to hide under and inside, and when there is not a lot of open space.