Both armatus and gatf can be fragile at that size, while dorado can be extremely aggressive. You can do it, but be ready for the outcome of them not last very long. Also, from a growth perspective the dorago will grow the fastest, then armatus, and then gatf.
Never kept these guys, just researched them. Took a try at a gatf, but failed. Those that have been successful are experienced keepers that keep dithers, and closely monitor the tank.
As pointed out gatf are sensitive. I think it'd be a ticking time bomb. Don't think dorado and armatus growth differ very much if at all. I'd think armatus grow faster actually. Not very often do you see someone raise their dorado to 2'. Armatus can be real aggressive too once they put some size on and gain confidence. I'm sure you know of dorados rep. It's going to come down to your specimens at the end of the day. You can give it a go. But it'll likely be a ticking time bomb.
Right now my arowana is about 7" and the pbass are about 6". They're faster grower than the GATF but they're pretty mellow (never seen aggression from them) and I can't see them getting big enough to eat the GATF. I could be wrong though, the more advice the better!
I'd worry about the bass outgrowing and eating them. Aros probably won't be able to catch the gatf in the case where it does outgrow the gatf. But both bass and aro will outgrow the gatf if it is the regular strand of gatf. Also pointed out is gatf get more solitary as they grow. With only two one may end up being badly beaten by the other eventually. So yes they'll swim together now but you'll notice it less as they grow.
I have 2 8" GATF in 280g tank. They don't bother other tankmates much but often nagging at each other ONLY! Not Bala Shark, not Tinfoil Barb, not albino barb. Sometimes one even got scratches but quickly healed. They did since the first day they met so I know I can only keep one when they grew bigger.