[quote=@hatakekuro]
Due to the caster class not being strong in the physical abilities department I think its fair for him to have the summoning.
[/quote]

It's mainly just the raw power of the noble phantasm. I'd limit the amount of phantasmal beasts he can summon to be one, because frankly not many servants are handling a Hydra well anytime soon. Monstrous beasts are ok.