Perhaps one could liken an artillery battery to that of a ship. You need a lot of specialists and losing any of these men seriously degrads the unit mission. Hence, maitaining their complement was a necessity.

Infantry units could be wasted away to almost nothing, yet they continued to serve.

I haven't a handle on CW artillery batteries, but here is the composition of a British Flying Artillery battery of six guns during the Waterloo campaign, commanded by Captain Cavalie Mercer:

Animal requirements:

5 guns, 9-pounders, and 1 heavy 5-1/2 inch howitzer - 8 horses each Total 48
9 ammunition wagons - viz. 1 to each piece, and a spare one per

division (2 guns) - 6 horses each 54
1 spare-wheel carriage - 6 horses 6
1 forge, 1 cirricle-cart, 1 baggage-wagon - 4 horses each 12

Total in draught 120

6 mounted detachments - 8 horses each 48
2 staff-sergeants, 2 farriers, 1 collar-maker 5
6 officer horses, lent them by the Board of Ordance 6
6 officer mules, for carrying their baggage 6

Total 185

Additional horses unaccounted for above, spare, etc. 30

General total of animals 215

Besides which, each officer had his own two horses, and the surgeon one,
making 11 more - so that, including these, we had 226

Enlisted staff included 2 staff-sergeants, 3 sergeants, 3 corporals, 6 bombardiers, 1 farrier, 3 shoeing smiths, 2 collar-makers, 1 wheeler, 1 trumpter, and 1 acting do., 80 gunners, 84 drivers

One has to marvel at the enormous logistical tail required of 19 century armies, and the consideration of such required of army commanders in their planning.