It Depends who your playing, if hes a noob with a ring hero, all have to do is kill the ring hero get the ring and finish him off,
If hes realy good its almost imposble unless you plan it well and u have many more men then he did before he had the ring,
I would say if you see someone that has got the ring and taking it to there base, rush then asap,
Its easyer to kill a castle then to kill a ring hero,
keep rushing nonstop, and keep expanding your base
keep him speading money, so he has to choose, save my money and face the risk of loseing before i build him? or build troops and defenses and a battle him back then build ring hero,
mot likeing he would do option 2. this give you time to do a siege rush
each side has seige units, build tons of these,(ents, trolls, trebs, etc)
build maybe 4 or 5 of these siege units with tons of (horses, spider riders, wargs) or other fast moving and deadly units, then them all hidden, then find some high ground and take out his castle.
Then rush in with ur fast units before he can recame his ring.
its best to fight ahead then facing a ring hero,
if you cant and he made a ring hero, you must kill it, when u do, you will have the one ring to build your own ring hero.
:P
just gota survive!