Did Gero f*ck up not getting Trunks or Gohan's cells? Or someone else's?

[Warmmedown]

Do you think Cell could have been even stronger with half-saiyan genes? Or would it not matter, because he wouldn't be a half-saiyan himself? Or would he become weaker, by taking him further away from being half-saiyan (assuming he got equal amounts of genes from Frieza, Cold, Vegeta, Goku and Piccolo)? Or would having some human genes make him stronger, due to a saiyan-human mix being uniquely powerful in a way that a saiyan-namekian-freeza mix isn't?

Is there anyone else he should have got genes from on Earth?
I feel like Chazou would have been good, for the powerful telekinesis (better than Freeza's).
And Oolong or Puar for the transformations - would've been much easier to absorb the androids that way.

 

[SSJ2]

I don't think it would have helped him personally. If anything having more dilution of Saiyan cells might have made him worse off. The fact that he was able to have a Zenkai despite being low SSJ2 tier tells us that Cell does not function like a regular Saiyan. Perhaps lowering his concentration of pure Saiyan cells would have reduced this effect.