If you count all the nodes in each subflow and multiply that by how many instances you have in your project, what number do you get?
E.g. subflow 1 has 20 nodes and the project has 5 of these === 100
Subflow 2 has 10 nodes and the project has 10 instances=== 100
Subflow 3 has 25 nodes and there is only 1 instance inside subflow 2 === (10 x 25) === 250
Here is another thread...
If your subflows are not storing state (like context) you could likely replace them with link-call subroutines. They only consume the number of nodes that are written.
