You should not have that problem to start with. This…
[…] for some reason, when I place those actors the same way in the viewport, at runtime it is completely out of sync, like : it got 5 unit, push it, the next turn it got 0, and the next time it got 10 units and push 10 units, so the flow become like : 5 / 5 / 0 / 10 / 5
… is not a thing (yet here we are! 
) under regular circumstances. What is irregular about the rest of the script, is a better question here.
The suggestion about the manager helps with optimisation, maintenance, scalability, debugging and, probably, will not solve the issue since, at least to me, it seems utterly unrelated.