There is no reason to "bulk" thats just bro science.
If your body needs energy to build muscle, it will just use fat stores to build it. You can build muscle on a calorie defciet.
However, if you feel the need to "bulk". You want lots of protien and carbs "carbo loading"(more bro science). Taking in fat wouldn't make sense since the broscience behind bulking says your body can't use fat to build muscle.....
Honestly if you want to gain muscle workout, and give your muscle rest. Give yourself plenty of protien.
No need to ignore your post, i know it works building muscle while on a slight deficit, though you need to be extremely aware of your diet, you can't realize by bedtime that you are lacking 40 grams of protein and just pour down 2 whey protein shakes down your throat. Lack of protein will cannibalizeyour muscles, since you're on a caloric deficit.
What i am after is to "bulk cleanly". No fast food, no overeating, just plain, nutritious food, while laying on a small calorie surplus.
The cardio though, i heard is good doing. It speeds up your metabolism and such and can increase your gains in the long run (don't know how to explain deeply) plus it is good for your heart.
Anyway, i am curious of hearing about your gains, how did you all do?