You don’t have to do Rdl or hack but a leg press would be needed at least, just leg extension and leg curls unfortunately won’t cut it if you actually want to build some legs
Some physique pictures would help here to give you more in depth help as to what you actually need.
We acuttaly have a pendulum squat in my gym. I like it alot. But dont progress. I Think it is beacuse the moment arm is to Long so when i put a 1.25 kg on it feels like 10 kg. I like the hack squat also but my hamstrings/adduxtor cramp up and it hurt really bad cant really walk after 1 set, what could i be?