help on making a multifinger cascode nmos layout

[syncmaster]

cascode layout

I am a beginner in RFIC design, and met some diffcuity in cascode LNA design, May someone could help me.

the following question assume the finger number is 4.

1.Should I merge the drain (common source nmos) with the soure (common gate nmos)?

2.If I merge the 2 nmos, how can I ensure that the parasitic cap of changed cascode 2 nmos is the same with the orignal schematic simulation?

3.What should I do to merge the 2 nmos, to aline them? in AABBBBAA
format or BAABBAAB format?

Thanks for your attention on my posts!