Well, this is a tough one.
I suspect a lot of this debate stems from differing concepts of tactical and strategic. To me, tactical always meant this: "The actions you take to win in a given battle."
So I went and looked it up:
1: of or relating to combat tactics: as a (1): of or occurring at the battlefront <a> <a> (2): using or being weapons or forces employed at the battlefront <tactical> bof an air force : of, relating to, or designed for air attack in close support of friendly ground forces
2 a: of or relating to tactics: as (1): of or relating to small-scale actions serving a larger purpose.
Now you have to notice that the parts are bolded, in a game, are fairly relative. What is a small scale? In X-Com, the small scale is your troop-movement during the actual fight, as opposed to your overall strategy during it and the Geoscape.
So the strategy is: "I will bring 8 Gauss Rifles, a bunch of armor, some proximity grenades and some heavy-duty explosive and my new recruits." for the Geoscape. The other part of strategy, during the battle, would be "I will give orders to kill all aliens around the Triton, then take over their ship."
The tactics are the actual execution by the individual soldier - how they go about doing what the strategy has dictated, and how it is implemented during the fight. The strategy - to kill all the nearby aliens - leaves a lot of room on how to accomplish this. You could send out the soldiers in pairs, having a scout spot aliens and having spotters use aimed shots at long range; you could throw grenades towards where you suspected movement, you could very carefully advance in small 1-man commando groups exploiting the terrain for cover as best as possible and vibro-blading enemies up close. That's the tactics.
What we're trying to find out is: Can Dark Omen / Shadow of the Horned Rat be called tactical even though it is real-time? If so, is it less tactical than a turn-based (roleplaying, for the most part) game?
Now you will see I tried to adopt a very fair definition of tactics. But it is also a relative one. Let's take Dark Omen as an example, which of course, as a given, gives us many strategic options. What regiments do I take into battle? Who should get XP? Who gets what magical item? What side-missions can I afford to take, and what troops can I replace with my limited budget? - I find this comparable to the Geoscape - albeit with perhaps a little less depth.
During an actual battle we have an overlying strategical goal - much like in X-Com. For example it could be "We'll take this hill, hope we can thin out enemies from ranged fire there, and then complete objective X."
To me, the actual execution of this strategy is what I have found to be "tactics". Where exactly do I move my troops? Where should they face? What spells would impede the enemy the best? What enemy is going to arrive first at what regiment should fight them for the least amount of losses on our side.
It makes, to me, no difference if these choices are made quickly, in real-time, or with all due thought in turn-based combat. I understand and admit that it is quite possible to say that TB has "more" tactical options- because it is much easier to give a lot of input in a smaller scale. This is why TB is (in certain ways) better than real time: you can issue a lot of commands in a single turn. It IS true that in real life things happen fast, but that's exactly why in a real time game, we can't keep up - unless we were Korean, of course.
so, uh, what's this all boil down to? I know I wrote too much. See, here's the gist: I think that RtwP and realtime can absolutely be tactical. I think I illustrated that well.
Now for the question, would Dark Omen be more tactical if it were TB- it's a tough one to me. But if you read my arguments it's absolutely logical to say this is true. You have to remember: I don't say this easily. I love Dark Omen the way it is, so I don't feel too well, but I have to at least respect my arguments laid out before: so I'll say DO is very tactical in its own right, but from what I said, it follows that if it were TB, it would be even more so.