Tactics benefits Dark Servant. He counts as a teammate for that purpose.
Dark Servant's pet "AT" and powers combine to mean that he has the same base accuracy that players do. That's to say that he has a 75% chance to hit even-level foes, 65% to hit +1, 56% to hit +2, and 48% to hit +3s. (Sorry, I'd have to go look up +4s, I committed that list to memory in days when they weren't as common in people's encounter list as I16 and the MA before it made them.) Those numbers are for foes with no defense - defense subtracts directly from those percentages.
I know that base accuracy level doesn't work well for me, especially when faced with +2 and +3 foes that people seem to face frequently in the upper-level game. Granted, his debuff aura is autohit, so he'll always be able to use that. I also like for him to be able to immobilize foes and potentially heal at least himself, and he can't do either of those if he can't hit well.
So I don't recommend him getting no accuracy without some toHit buffs. But you could probably make it work. In a team setting, I'm not sure how many people would notice if he was missing a lot. 
Blue
American Steele: 50 BS/Inv
Nightfall: 50 DDD
Sable Slayer: 50 DM/Rgn
Fortune's Shadow: 50 Dark/Psi
WinterStrike: 47 Ice/Dev
Quantum Well: 43 Inv/EM
Twilit Destiny: 43 MA/DA
Red
Shadowslip: 50 DDC
Final Rest: 50 MA/Rgn
Abyssal Frost: 50 Ice/Dark
Golden Ember: 50 SM/FA
That's great, thanks for the info. With a bit of squeezing of set bonuses, I've found the extra slot so I think I'd rather have Fluffy hit better, especially on a team build.
Many thanks. 
@Dante EU - Union Roleplayer and Altisis Victim
The Militia: Union RP Supergroup - www.themilitia.org.uk
Hi folks.
After having spent a lot of time on my other toons, I'm coming back to my first level 50, my D3 which I'd forgotten could be so much fun on teams. In trying to get a bit more pleasure out of playing him, I've been slotting for damage buffs and defence while still maintaining the usefulness of all the powers however one question has arisen that I don't know the answer to.
Fluffy is so difficult to slot given his multiple powers and how many sets go into him but one thing is universal, I've always tried to give him some accuracy slotting. However on this build, I'm struggling to find slots and have had to sacrifice the accuracy slot I would normally give him. None of the sets in him enhance his accuracy so I'm pretty much relying on his base accuracy. What is other people's experience of this? Will he suffer without that accuracy or is it necessary. My build doesn't contain anything like Tactics so he won't be receiving any external buffs (not that I'm sure that Tactics would buff him).
Worst scenario is I take the second slot out of Fly and resign myself to being a bit slower.
Thanks
@Dante EU - Union Roleplayer and Altisis Victim
The Militia: Union RP Supergroup - www.themilitia.org.uk