@Option 1
Option 1:
If we attack Asoka first, are we solely relying on a high Power rating to keep Liz from intervening? So let's say we build 2 Battleships to block the sea approach to the city & protect the Fish & Clam. That means 8 Tanks will be available to invade India. That will be more than enough to wipe Asoka out.
But if Liz does intervene to help Asoka, things will get a lot messier. Liz could send troops to attack Washington & Hamburg at that same time. That would stretch our forces thin, but we can still hold. And whatever losses we sustain can be made up for quickly given our current

output. What I'm more worried about is whether Caesar would send troops to capture cities if there's a large stack threatening Hamburg from Kyoto. If Caesar starts turtling, the war will stall very quickly.
Yes, we would be relying on high power and lack of bribing options for Asoka, Liz is more advanced.
There are problems with this option of course, it's risky.
Sea defense:
Those 2 battleships wouldn't be enough. Liz is surely building battleships atm. We have 2 options:
1) Ignoring the seas
We would lose health bonuses from Fish and Clam but we could get that back using Uranium, Cyrus would sell us Fish and Clam for that. Losing the Crabs would mean additional -12

for a total of -13

We could compensate with farming the forests, we could pre-farm them now. That would bring 6 more

. If we build the supermarket, we can get 3 more

. Of course, we need Refrigeration for that. We would also need 4 more fishing boats eventually, that's 4 more turns to build them.
Basically, this doesn't look like a good option.
2) Defending.
We would need at least 5 battleships, IMO. Liz will most likely build at least 3 battleships.
That means 5 more turns.
JC's movements could be problematic, this plan could get really messy. Our defensive stack in Kyoto would have to clear things up fast to reduce problems for JC.
Btw, Asoka has 2 war elephants. Gunships are strong against tanks, 48 vs 28. We have to be careful about that.
@Option 2
Option 2 lacks exact numbers and the required time. More importantly, option 2 has a major misconception. We don't have to fight Asoka too if we attack Liz! Asoka won't help her, he is cautious at our team and only pleased at Liz.
Option 2 should be the attack on Liz only. We need exact plans and numbers for that. Here are the garrison numbers:
Liz
Kyoto
4 inf, 2 art, 7 SAM, 3 WE (city)
4 art, 4 SAM, WE (farm tile)
York: 3 inf, 6 art, SAM
Nottingham: 2inf, SAM
London: 6 inf, 5 SAM, 3 art
Ships: 5 destroyers, battleships expected.
Liz will also build marines, her numbers will increase.
Our forces:
Beijing: 5 inf, 2 MG
Washington: 14 inf, 11 art, 2 MG
I estimate that we'll need ~10 tanks, ~10 marines and ~5 battleships. That's at least
25 turns of preparations.
Let's try to make exact deployment plans for the war with Liz, we have to plan this now. Try to find mistakes and weak spots in plans, that's the best way to find the correct approach.
Mech. infantry
We'll need lot's of cash to upgrade the soldiers, we have ~25 units for the upgrade. GP will be born in ~10 turns, let's hire merchants and gamble for the great merchant. We also have to take more cash from JC, reducing the slider to 0% would be too slow to accumulate all that money.
@Classical
Thanks for the info, I forgot about the tiny map setting! This means that other civs also have Oxford, built in better cities than Berlin. JC wasn't able to build it in Rome, he already has 2 national wonders there.