Thanks for the great feedback.
Actually there is no smart algorithm behind it, just that deckplans are the most unlikly item to spawn.
20% for Deck Plans on Cabin and Leisure Deck
40 % Weak Health on Cabin and Leisure Deck
40% Health on Cabin and Leisure Deck
I intentionally introduced the medical deck to ensure the player can heal befor the last deck
If I have the time to iterate on it I will certainly add at least an upper limit how often deck plans can spawn per level.
The idea to adapt available health stims on enemies or vice versa is also something I will consider if I happen to work on the game again.