Yeah, sorry you can have a small workaround by maintaining silver status on the other card, that's true.

On the other hand then you'd need to travel every 12 month cycle at least 60k and total of 180k over 24 months is really close to 210k, in my opinion, especially as it's needs to be 60k+120k per consecutive 12 month periods...and like said above by Petropous, that to work you'll need a really steady stream of points.

Another point: With your scheme you're basically crediting all flights to an account which is silver, or even basic in the start. This means that your status in terms of reservation/pax manifest information is always silver, even if you had a gold card in your pocket, which you use solely for lounge access. AY doesn't give a s**t about status but many other OW airlines do so for op ups, cancellations etc. you are a bit better off with sapphire on the reservation.

My advice: stick to one account, AY/OW status is really not that important anyway and if you really need basic level of lounge access get the priority pass for your Y travels