Upping an Arsenic and Titanium Shield could be rather beneficial, though I don't know if it is anywhere near a must.
You are right there, using the upgraded cards here won't make a big difference.
But I wouldn't want to risk too much. A simple upped shield of the other element can already cancel out a arsenic (though I doubt they will use something like that). It's not like that one card less will make us lose the war so IMO we should go here with upped arsenics, we might as well add a upped flying weapon here.
hmm, ok, i can find this deck would work, but can i get upped shields? 1 cards for 2 diamonds and what, a gavel or so? or 1 titanium, 1 diamond and a gavel?
would hate to see pufferfishes to poison me down 
but for care, i will win without this cards upped, if not wanted 8) 
We don't have a gavel/hammer in the vault, so that won't work. But upping the shield to counter pufferfish is a good idea, so you can use the BB's on more important stuff. As for the 3rd card, I'd suggest an upped pillar since I can't see anything much more usefull to add as an upped version.
