Why would Dominion benefit from the lack of (or fewer) summoner spells? Here's a similar question: What would Dominion be like with 3 summoner spells?

3 summoner spells: Exhaust on everyone, ghost/flash on everyone, a spare slot for garrison/promote/ignite

1 summoner spell: Exhaust would be your only pick, someone with promote would gain nothing but lane push potential, garrison would be very useful cause you dont' have to fear so many exhausts, ghost to get around the map more scarce

Summoner spells are so important to League of Legends in general, they would not do anything major so changing summoners is something we will never have to worry about.

Also, why would you want less spells to use during such a fast paced mode with so many spells? I would agree with a small CD reduction on the spells for dominion but not the removal or addition of a slot.

Lol...I bet your mad cuz someone ghost/flashed away from ya huh?

Been there...sucks :S