Z590-E 3 SSD Config

[TheBlahBlah]

Hi

I will have only 3 PCIE M2 SSDs on my build:

11700K with Asus Dual 4070 and:

M2_1 Samsung 990 Pro 2TB

M2_2 n/a

M2_3 Samsung 970 Evo Plus pcie 3

M2_4 Samsung 960 Pro pcie 3

No any Sata drives will be used, so is this correct and fine?

Because I think no more PCIE lanes so left M2_2 blank

Am I right or there's a better arrangement suggested?

Will using both PCIE 3 and 4 will share and reduce their pcie 3 speed?

Thanks