Look in turn by even suggesting we get all of Coil in raid rou, you're forcing ones like T9 to be a part of it. Giving people something like T1-4 is only giving them a snippet of the story and in turn brings more posts on here asking "Why aren't the rest of Coils in here!?!?" which then we need to have this whole conversation again about them. If you yourself have to argue that T9 is too tough for duty finder then do not be in support of Coils. You either get them all or get none. That's like if Alexander had only A1-A4 and nothing else in normal raid rou just because.
I want to state as well these rous are meant to be your daily login things, something you do each day just for the sake of it. It's not meant to be a taxing deal, it's just meant to be done at a casual pace. Even in these rous like normal raid people still abandon on O11N, O12N, and E4N. The amount of times I've been put into O12N as a party in progress was insane, because people can't actually handle the split tanking. If you're telling me these knuckleheads are the ones you may be stuck in for Coil and we have to votekick them out or leave and eat our penalty to escape is a load of bull.
If they had a specific coils rou, for the purpose of just running just that I can see that being a thing, HOWEVER the interest in that rou would be very minimal and I'm sure the majority would rather opt in for unsynced story runs instead after trying some of the fights synced. Hell a rou should be given instead to like Rival Wings instead. Something that requires more people, and is absolutely dead enough that a discord community has to bring up the slack for SE and them not making an actual rou for the damn mode for daily bonuses.
I know your heart is in the right place, I really do. But for something as casual as normal raid rou is meant to be we do not need the Coil baggage. We are not doubting the player base being able to clear this content, we are more so doubting the DF base to not clearing the content in an efficient manner as based on previous experiences between 8/24 man content and the current DF trends of like leaving after a single wipe.
I'm sure by some miracle a bunch of randos in DF would clear a fight like T9 after enough effort, however for a payout as small as normal raid rou gives and the amount of time/frustration put into just getting that win doesn't make any sense, especially when the looming thought you could do it all over again tomorrow with a new set of people sticks in your head.