I am no coach nor a good player, but I do take an interest in this type of thing and can repeat what other say.
In a similar way that golf coaches have lots of differing views the same can be seen with cricket in terms of what you do different with the kit you use in practice.
Baseball you will often swing heavier bats or two bats in the view that you will find you match bat lighter in the game situation.
Some cricketers do that. calling wood being seen with what looked like a 4 lb club in practice a few times.
Most, I would guess use very similar, but " lesser grade" bat in the nets , as to not use up the good willow in practice.
some don't care either way and will use whatever, when ever.
More batsmen now have different bats for different situations, i.e. T20, or different batting positions or needing to finish a game off quickly and will practice these different requirement sin the nets with different bats. I saw something the other day where Chris Nash of Sussex said he did this, but sometimes he would pick a heavier or lighter bat for practice " just to keep me thinking"
I guess in short... Whatever works for you. First thing is to practice, then fine tune what works
I guess using different weights can justify more bat purchases!