certainly,, once per week can work as many people get gains on it,, but it is not optimal and many people will get crap results,, specially when doing routines where you dont even get some indriect effect,,
twice per weekw ill grow you better but you need to program it in smart way and dont go overboad with volume,, there is also middle ground betwqeen oncer per wekke and twice per week...
i been into bodybuilding many years and trained many people,, and exactly how youset up routine is abit of e xperimentation...but 3-4 sessions per week is best for most people,, some train more but in most cases they shouldnt ,, 5-6 is just overkill and many cases those who go 5-6 times are half assign many of thw workouts,, for sure some some can go that many time and train hard,, but highly quesitonable if they should,,...anyways most cant and shouldnt because recovery doesnt allow it,, life stress doesnt allow it,, work doesnt allow it,, wife doesnt allow it
these are good base routines;;
2-way split,, ,,3-4 session per week
2-way split + 1 full body day 3 session per week
2-way split EOD ,, 3.5 session week
3-way split,,, rotate over 5 days but you need good recovery ,, most can not do this on regular bassis,
3-way split,,, push/pull/legs...everything trained every 5---sometimes every 6th days,, can work,,
3-way split EOD,, every thing every 6th day,, can also work but its on the edge,, but don't do it push/pull/legs style do it chest/arms, back/shoulders, legs or chest/back,, delts/arm ,, leg...to get abit indirect effect too,,
what you pick depend,, you need to experiment and see what you like and what your body likes,, and what you have time to do,,
when you trained many years you go to unbalanced trainining,, still no need to go in gym more than 3-4 time per week,, instead you go maybe 2/X on those days,, but you do it in a smart ways always,.. or you dont do it all,,
i seen pro bodybuilder and high class anmaetures built via 3 sessions per week,, total crap that you must go in 5-6 days / week!!