I mean I currently have 133 from just grinding out the game and two lucky pack pulls but mainly just been playing and bought some cheap guys because i liked the cards all NMS so its really not hard to do both. I have a bunch of the live series collection done aswell besides like the angels, dodgers, rangers and mets being the ones that are extra expensive as i got lucky and packed judge.
You can definitely grind both as live series will be useful once set 2 and 3 come around for captain teams and when set 1 cards get phased out plus in restricted events that only let you use certain cards like the core cards from live series collection and BR/Ranked i believe.