Just frames are OK, I guess, like Jean Kujo's VF5FS 1-frame-link guaranteed on block string.
But where are you going to find tough links if DOA specifically has a string system? You can't. You can have harder delay intervals, but you cannot have links in a 3D fighter. VF has just frame strings, but not tough links.
DoA has a lot of strings, but not all attacks are strings.
In SSF4, if I use Deejay and do cr.lp>cr.mp it was a 2 frame link, IIRC.
In DoA, if an attack is +15 on hit and you want to follow it up with a move that has a 13 frame start up, it will still be a 2 frame link, wont it?
Even though DoA exists more on a 3D plain than SSF4, I would have thought the same principle applies, when it comes to implementing "tough links" into a fighting game.
I'm in with more guaranteed ground combos. Maybe a bounce that happens when you use a downward smash attack on an aired opponent. The bounce would only be big enough to get 1 or 2 mid attacks from. Like Mila's 3PP on aired opponent per se. You can do 6PP after it. For example, this would be good with characters like Zack, Jann Lee and other fighters, but not so much grapplers. Where would they get guaranteed ground grabs? Unless not ALL downward smash attacks do a bounce. Some do what I call "KD" slams. Where you could get a guaranteed forced tech or a ground throw.
I like your idea about limiting hits (and damage?) when you have guaranteed combos. But Im not keen on the whole "bounce" part. The bound/bounce system that was introduced in Tekken 6 (?) was one of the worst things I have seen in a fighting game. I wouldnt want to see something similar in any future DoAs (I thought it looked as silly as Rachel bouncing her DoA opponents off the ground).
Maybe if the DoA system offered less counter opportunities during a series of ground/standing attacks, to allow certain follow ups to be guaranteed?