They have interacted...quite a bit. DS is originally a Titans enemy noone can argue with that, but since Identity Crisis DC has tried hard to make him become GAs nemesys...because let's be honest: Merlyn in the comics isn't half as cool as the show's version (I'm speaking background, characterization and reason to be Ollies archenemy).
i know lots of people don't read the GA comics (or have just read Longbow Hunters and Year One)...but Ollie became a real badass after being resurected by Kevin Smith. Shortly before having to deal on a regular basis with DS he retrained himself and even Slade had to admit that - although he was not near his level - he had become very good.
Before Identity C. (Where their feud starts because Ollie stabs Slade in the empty Eye socket making him unprepared for the Leagues attacks) they had only interacted once as far as I know in a horroble tam up(this was during GAs weakest run) but after that DC has tried to present them as a pair quite a lot.
-Deathstroke was from then on featured a lot in GA comics
-In the Injustice commercials and Demos they are shown fighting against each other prominently (the GA reveal Demo featured a fight against DS)
-The toys for said game were sold in a double pack GA/DS (not DS Dick Grayson or DS Cyborg or DS Raven).
-Having DSs mask on the island in the pilot was not the writers idea it was suggested to them by Geoff Johns.
-In the N52 the two have not met yet but in the Futures End storyline it is made clear that they will become enemies somewhere in the future and DS kills Ollie (saying he would have done it for free when it comes to GA...therefore hinting at some deep hatred)
well I'll say this I'll take. the original comic Roy over what's happening here any time and huntress too. the one that's actually the same age as Roy hell I would have been happier if she was a love interest rival to thea since I think Cheshire will be a while befor we see her she becomes Roy's baby moma. the writing some times on this show . let's just say it can be way better
maybe they needed another villain beside malcome but they could have done alot with his time with being waller's forced assassin to do that have an enemy from his or one of his Argos agency trainer not the one with a family in china mind you, but another person just for the show with issues.
This is what been bothering me most other shows or media with the spy world they show case some one being taken in by a agency, that agency makes them better / improves on the skills they have and train's them in stuff they lack. from the what they have learnt prior.
But here cause it's waller he's not being improved cause of how she well using him. well that and he's resisting for good reason. I'm aware that part alot is off.
This reminded me when death stroke in the show was out thinking Ollie tactically & strategically. then after he defeated death stroke they said ollie was taken in as operative /assassin that was what bugged me. If he was with an agency that should never have happened cause he would have those skills & slade /death stroke wouldn't have out maneuvered him like that.
let's just say every time I see some one from the fan base say Ollie should train someone like Roy, Helena or anyone it bother's me. he's not at the level he should be, not in tactic's , strategy or detective work even with stuff after Sara death on the roof with Dig, no he's(Oliver) not there yet he shouldn't be training others.
Oh that was the very thing that made Roy cool in the comic's the CBI agency that took roy in after ollie wasn't the best guardian to him made him a way better fighter and trained him in stuff Ollie didn't pick up til most of his kids adopted or blood related surpassed him at skill wise. Roy actually had detective skills. Ollie really should have had a CSI or forensic person look at Sara's body to find out height of the killer . from where the arrow's hit her.
Yeah in a way it's sad they (most of his side kicks or kids ) passed him in certain area's of skill, but it did help to define some of the characters from each other . And it let them each have different skill set's they were each masters of or specialist in.
Best of all they learned it from, other people.