Here are some other translations of that passage (Enchiridion 26): https://enchiridion.tasuki.org/display:Code:e,ec,twh,twr,gl,...

- The first part says: if you shrug off someone else's cup being broken as just an accident, you should also do the same when yours gets broken.

- Then he clearly says “Apply now the same principle to the matters of greater importance.”

- The last part says that if you respond to someone else's bereavement with platitudes like “Such is the lot of man” or “This is an accident of mortality” (this does not preclude some amount of sympathy and compassion preceding those statements!), then you should respond the same to yours, rather than thinking of yourself as uniquely wretched and unfortunate.

The main point is about being consistent in how you view others' fate and yours: not that you should care equally about someone's wife and yours (or that you should be indifferent to either), just that the story you tell about life and fortune should be the same.

[He's also obviously distinguishing the cup situation (a simple everyday thing where the principle is easy to see and follow, given as an establishing example) from the wife situation (a situation where the principle is harder to apply), by saying “greater things” / “higher matters” / “matters of greater importance”.]