Well arsenal got a striker just not a good one so it's more than what wenger usual does for you
Wenger buying long term solutions to short term problems is actually what Wenger does constantly. Panics and needs some left back cover, buys Santos... gets very lucky to offload him after what 12-18 months. Buys Chamakh, gives high wage 4 year contract, uses for 6 months, etc.
Giroud is out, need a loan striker for 6 months... buys an expensive crap striker on a high wage for 5 years.......
The problem is Wenger spent the entire summer and the past year really saying Giroud is brilliant and we aren't going to be looking to replace him. He's still in Wenger's eyes first choice.
What does he see happening now when Giroud is back, Giroud is pretty crap as a centre forward, he has absolutely no skill set to play as a wide forward... so Giroud upfront, Sanchez wide, Welbeck or Walcott wide? He loves Walcott, with significantly higher quality players available who are good wide he's dropped them for Walcott whenever the little idiot is fit. So what, Giroud, Sanchez, Walcott wide and Welbeck dropped? Drop Sanchez for Welbeck, or drop the guy who for 5 years he's screwed over much better players for? Either way, it suggests Welbeck out wide long term where he is completely hopeless. That or he changed his mind and wants to drop Giroud for Welbeck, in which case, we change one expensive 6 yard box tap in artists for another expensive 6 yard box tap in artist... in both cases lacking any of what we need upfront. Genuine quality, genuine threat from either isolated or genuine ability to take the ball more than 20 yards and not fall over the ball.
There is no scenario in which Welbeck is a good signing, I won't be surprised if he ends up being dropped if when the other three are fit, so very expensive(for us) back up wide striker.... where Welbeck is even worse. Best case(for Welbeck) is Giroud is dropped long term... but he's not an improvement, most of his goals are the same type, and in every way in which Giroud utterly lacks in his game... so does Welbeck.
Wenger has screwed this club over and over for 8 years, he's done it again, he'll probably do it again in Jan even if it's just by refusing to buy anyone we need or sell someone we could be using but just won't(Campbell or the like).