The huge difference in their energies weakens the Sagittarius and Cancer work compatibility. Fire signs and water signs typically don't mix well. When discussing together, Sagittarius must make the effort of taming their tongue so they won't offend the water sign, while Cancer should not take everything the fire sign says to heart. Also, Sagittarius wants to do everything as quickly as possible so they can move forward to new tasks, leaving Cancer—who often pauses to reflect on their progress—behind.
There's not much left to do to improve the Sagittarius and Cancer work compatibility. Instead of forcing their partnership, it would be better if they pair up with other signs whose energy complement theirs.