Hi DelDance,
Great question — you're not imagining things. The foot action is very similar between the two, which is why they can feel almost identical at first glance.
The difference is really about position and shape, not the step itself:
5th Position Breaks
• Danced arm-to-arm (not fully side-by-side)
• The couple alternates between promenade and counter-promenade (a slight “V” shape)
• The turn is smaller — about ¼ turn from side to side
Crossover Back Breaks
• Danced in a true side-by-side position (no “V” shape)
• Typically hand-in-hand
• The turn is larger — about ½ turn from side to side
So while both figures use a back break action with similar footwork, they feel different because of how the couple is aligned and how much they rotate.
That difference in position and rotation is what gives them separate names in the syllabus.
Fun fact: 5th position breaks get their name from 5th position in classical ballet, which is a toe-to-heel foot position. In practice, however, ballroom 5th position breaks are more typically danced with feet a couple of inches apart -- which of course is not a true 5th position in the strictest terms. But the name has stuck.
Hope that helps clarify it!