[kunwarkharbanda]

Here is my suggestion 

You say that attacker   can choose the opponent in enemy guild to attack 

So why cant we even make that a live PvP?  That would.make more sense

Here it.is

The attacker  decides the opponent from enemy guild 

Once opponenets are decided
Both.opponenets picks multiple times out of 24 hrs when they can be present

For example player 1 choose 1-2 pm 4-5 pm 8- 12 pm

Player 2 chooses 3-4  pm 12-1 pm  9-10 pm

So the common time is decided  which is 9-10 pm

Now that time is decided  live pvp can happen 

At 9pm both playwrs do pvp. If the defender  isnoffline  the attacker will face comouter controlled team like elo 

If players  arent present there we can have the  computer controlled battle being suggested now but atleast  we gave chance to others to defend and beat in a fair way

live pvp is not doable for no other than instance based events

in no game i have seen such system. all of the popular games uses offline match

so you better try to work on AI decision system improvement

why to even have that live pvp feature when its of no use 
anyways i give up.