As the founder of the Hippo-Unchained alliance, Malaysia faces multi dimensional adversaries within the neighborhood.
With more than 200+ members, Indonesia alone can dwarf the population of 70+ members of Malaysia. But, it doesn't stop there. Thailand, Laos, Cambodia, Brunei, Australia are also within the adversary alliance closer to both Indonesia and Malaysia.
Meanwhile the closest ally is the Philippines which does not have enough player count to counter any potential annexation of Malaysia.
India, however, has the player count which is larger than the Indonesian one but ...
Without any allies nearby, India just like Malaysia, has found herself with Pakistan, Sri Lanka, Bangladesh as the same hostile alliance which effectively drains the resources to contain India. Even though India has a much larger player count than the neighbors and sometimes is capable of neutralizing the hostile neighbors, the hostile alliance can make India and the other recovering allies of the Hippo-Unchained to sign a peace treaty because the adversaries have annexed the weaker allies as Malaysia which is harder to recover over & over if annexed.
Even though China is a part of the Hippo Unchained alliance, the player count is negligible to protect her own land from being annexed by neighboring countries.
India is left alone with the hostile neighbors just like Malaysia and the Philippines.
[Meanwhile, Myanmar(part of the Emerald Accord) works as a buffer/neutral zone between South Asian & South East Asian alliances backed by an alliance of the entire North American continent. It seems neither India or Thailand(adversy alliance) wants to annex that part to reach out to the other part of the subcontinent.]
Any progresses from land conquest by India can be reversed with peace treaties that India is obligated to sign for the greater good of the alliance.
In other words,
The Hippo-Unchained alliance is stuck with a resource draining masterplan of the nearby adversary alliance(SMD) which can always have an upper hand against this alliance until a change happens for good.
A few points to add:
Even with the players ability to fight for allied nations, the country itself can't attack directly to the hostile nation unless it shares a border with it.
If the neighboring countries are part of the hostile alliance, even with a vast player base, the resources will still be drained(India-Pak wars) by constant engagements after the peace treaty/NAP ends.