I was thinking the other day i have always done basics class since a started jiujitsu few years back. I think it's a great compliment to your advanced class. I do the basics then advanced straight after. I think if you just do advanced class you get lost in a myriad of moves and build togther a string of possible moves for the 'what if he does that' 'and i do this' case
Just my opinion but for me the basics classes string togther everything. The basics class is often called the beginers class but should be called bjj fundermentals because everyone needs to do it no matter your level.
Just my opinion as blue belt maybe i may change down the years when i advance
I must of done millions of shrimps but i am still looking for ways to improve it.