Think you're making a big mistake replacing your best player in this window. You'd have been better waiting till the summer
I see what you did there.
They've not replaced him. Not one player they've signed replaces what he brought to the side.
It's like suggesting VVD has replaced Coutinho.
Doesn't have to mean direct replacement. We've adjusted ok in the immediate short term without him so far, before adding Mkhitaryan & Aubameyang into the mix.
Eduardo didn't bring what Henry brought to the table either, but the full team adjusted & almost felt a weight lifted off their shoulders when he left. The ideal scenario for us would be something similar, (but without a leg break & a Gallas meltdown).
The problem is the guys you are signing don't do much to bring down the average age of your squad. You're becoming a bit Everton like in that most of your important players are not young. If Aubameyang signs you'll have Cech, Koscielny, Monreal, Mkhitaryan, Ozil and Aubameyang aged 28 or above. Signing Aubameyang just reeks of kicking the can down the road to me. If Wenger goes out soon the next manager will have an almighty job on his hands transforming the squad.
It is a bit of a worry, but there are still younger guys there. The guys you mention have a spread of 35 to 28 there, so it's not like they all need replacing in the same year. Then there's the other guys in the squad, like Bellerin, Mustafi, Kolasniac, Xhaka, Ramsey, Wilshere, Lacazette are all not included in the list you mention. Then there's the younger guys like Chambers, Holding, Mavropanos, Nelson, Maitland-Niles, Nketia who you would hope improve.
Like i said, i can see him signing a younger attacker in the summer, we've certainly been looking at them.