If the alloy was properly mixed to start with it won't matter whether the bullet came from the top of the pot or the last ladle full you can get out from the bottom.
A good casting routine should yield bullets that don't vary much over 1 grain.That won't affect for accuracy out to 1000 and will certainly work for silhouette. Weighing is good to sort anything that may have caught an air bubble or the blocks were completely closed etc.

As you say, not to start a fight...

But, I read a book about H.M. Pope and his procedure.  It included correspondence with Mann and others.  He made a couple blocks from wood and drilled rows of holes.  He would pour a dozen (+/-) bullets before he started keeping them.  Lined up in order cast in rows.  His theory was that, as members here have posted, that any differences as pot level and fluxing changed the cast; bullet changes would be minimized.

My first real Schuetzen rifle was a Miller.  Dean and I came up with the idea that a shorter case with smokeless could make for better scores.  That was the 32 Miller Short.  It seems to be doing well these days.     Dean was a proponent of the as cast storage.  I have always done that myself.  It seems to hold weight tolerance to the .1 grain standard I use.

Rich

I also shoot in the order as cast. But one also has to have the ability to continually cast bullets within a variance of no more than 4 tenths through out a batch to end up with match quality bullets. This is in regards to 33 caliber or less for use in competitive benchrest matches. Does it really make a difference? it does in my own mind as it is another possible variable that is being eliminated. 

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  If you are superstitious, shoot them in the order cast. Otherwise it makes no difference.

I just pick then out of the tub, load and shoot them. They are already weigh sorted.

westerner wrote on Mar 5^th, 2022 at 7:59pm:

Pretty sure when your cast bullets are “casted” they ben sorted into groups within the caste system

From top to bottom in the caste system you have 

Match, target. These are your elite bullets, best of the best.

Match, silhouette. These are simply the best.

Sighters, used to get you on paper

Foulers, just need to get out of the barrel in the general direction pointed.

Unshootables, worst of the worst. Considered unclean. Immediately back into the casting pot to hopefully be reincarnated at least as foulers, preferably as Match cast.

All casted bullets can be re-cast after being thoroughly cleansed in the melting pot and cast again in the caste system.

Una cosa más, after you cast, weigh, sort and lube your bullets, be sure that all the bases are clean and that they don't have any lube on them. You don't want powder sticking to the base 'cause it'll cause a low shot.