There is absolutely no problem doing that. Just make sure that each controller (including the engine) that are on the same CAN network have unique node ID.
The way I see it, simply use a Input Expander Module and install it near the pumps. Connect the sensors to the Input expander and connect the Input Expander into the "Engine" CAN network. Make sure to change the default node ID of the Input Expander before installing it into the network. Program your MC088 to receive the sensor data correctly from the Input Expander.
Sam