Middle-of-the-road and Matter-of-course

Middle-of-the-road adjective - Avoiding major social change or extreme political ideas.

Matter-of-course and middle-of-the-road are semantically related In some cases you can use "Matter-of-course" instead an adjective phrase "Middle-of-the-road".

Matter-of-course adjective - Expected or depended upon as a natural or logical outcome.

Middle-of-the-road and matter-of-course are semantically related in usual topic. Sometimes you can use "Middle-of-the-road" instead an adjective phrase "Matter-of-course".