Fewest GLOs with all of the Greek Letters among them.

[angels&angles]

Greek Alphabet:
Α Β Γ Δ Ε Ζ Η Θ Ι Κ Λ Μ Ν Ξ Ο Π Ρ Σ Τ Υ Φ Χ Ψ Ω

Okay... so we obviously have to start with the odd letters, so

Alpha Xi Delta
Psi Upsilon
Sigma Gamma Rho

We have left:
Β Ε Ζ Η Θ Ι Κ Λ Μ Ν Ο Π Τ Φ Χ Ω

Not sure how best to combine those . Add Chi O and Phi Mu, maybe? I'm only super familiar with NPC and a few NIC.