Just thinking out loud ... wolfguard with power weapons = 28 points of A4 LD9 SV3+ on the charge
Honor Guard = 35 points of A5 LD10 SV2+ on the charge
so ... what're the compartive advantages of the two? (setting aside the obvious fact that they're in 2 different armies)
WG
1. Cheaper
2. Can upgrade (for more points) to Terminator armor (then you're at 38 pts each)
3. Can take 3 squads of them without paying for a unique hero
HG
1. Artificer armor = sweeping advance
2. A5 on the charge
3. LD 10