@aroosaawooga This is a great question and makes sense.
I specifically put the type of exercises in this order because most of the research that has been done on HIIT has been done on aerobic exercises (cycling and running). HIIT was primarily researched using aerobic exercises because it is easier to control and measure the intensity of the exercise. Also, most people are already knowledgeable about running, cycling, walking and the endurance benefits have been established.
Bodyweight exercises are next on my list because there has been some research on this, but it may be more difficult to keep the intensity as high as you would be able to do with aerobic exercises. The benefit of body weight exercises is that you can still get cardiorespiratory benefits and also strength benefits. Bodyweight exercises can also be done anywhere at anytime, so this gives it another benefit.
Finally, I put resistance exercises because resistance is traditionally used for strength training and building muscle. One of my favorite exercises in this category is the kettlebell swing because it is an all-around powerhouse for building strength and endurance at the same time. There have also been studies done on HIIT and kettlebells. However, I think that resistance training should generally be used for traditional weightlifting and there is a greater likelihood of injury when combining resistance training with HIIT and improper form. That's why it's third.
TL;DR: There are different benefits and you can choose your exercise modality based on your goals (cardio, cardio+strength, strength), access to equipment, and your preference for a certain type of exercise. I personally prefer aerobic HIIT exercises and Kettlebell HIIT exercises.
