I do Caroline 4/5 times a week, and do 2x5k runs with hills for cardio. Sometimes I switch things to stay interesting, or if an area is feeling sore. Always at least one complete rest/no exercise day, though might go for a walk or dancing in that day.
To get best result ou need to follow the programme, but if you’re happy with more general strength and fitness you can mix.
some programmes, such as fuel, heat and endgame have cardio. Endgame is my favourite, especially the final finisher!