Do parallel LNAs at 90-degrees to eachother reduce the noise floor more than side-by-side?
In general the answer is no but....
If you know the frequency of your wanted signal, you can delay the combined signal+noise to produce the inverse of the original wanted signal. If you then subtract the original signal from the delayed version, you get a 2:1 amplitude improvement in signal.
However, because the noise is presumed to be uncorrelated (and won't therefore &quot;merge&quot; constructively to a delayed version of itself), you will get an SNR improvement. Consider three delay stages like this: -

I have two nodes labelled Vraw and Vout and here are the waveforms: -

The red trace is Vraw and the blue trace is Vout. As you can see, there are some noise improvements. If I tripled the stages I get a further improvement thus: -