Steps to reproduce:

1. Download and import attached project.
2. Open scene: main.
3. In the Hierarchy select FireBall.
4. Simulate, inspect how many green particles are there. (particle_editor.gif)
5. Press play.
6. Inspect the particles. (particle_player.gif)

Actual result: Particle system looks differently in the player and in the editor.

Notes: "Green" is sub-emitter of "FireBall" particle system;

When Green max particles is 1:
Editor: Only one particle appears for every particle of FireBall.
Player: Only one particle appears for whole system.

Reproduced on: 5.4.0b1, 5.3.1p1, 5.2.4f1