What you are saying might work in the last century when military is more of an industrial-era product. Back then, technology is simple and there aren't options when it comes to asymmetrical warfare. Today, That's not true. 30% larger than the US equivalent is a silly waste of resources. It would be much better to spend that 30% on other emerging technology, more inline with the idea of asymmetrical warfare.You stated that an excessively large Chinese military would deter the smaller ASEAN nations from embracing more trade with China.
I'm pointing out that if the Chinese military demonstrates a significant margin of superiority over the US military, then the smaller nations of ASEAN will give up trying to use the US military to help balance against China.
Then the smaller nations of ASEAN will prioritise relations with China over the USA, from both a military and economic perspective.
Defining an "excessively large Chinese military" is another question and depends on the goal.
From a requirements perspective
I understand you view is that 7 Chinese large carriers would be required to match say ~7 US large carriers assigned to the Indo-Pacific.
And that this is the optimal Chinese response to encourage the smaller ASEAN nations to maximise trade with China.
But my view is that the smaller nations of ASEAN will still see the US as a viable military ally, because they know that once the US redeploys its carriers, the US will be able to control the waters beyond the 2nd Island Chain. That will encourage some factions in ASEAN to resist a deeper economic relationship with China.
In comparison, if China has blue-water navy which is 30% larger than the US Navy (with say 13 large carriers), it's obvious to everyone in ASEAN that a military alliance with the USA is pointless because the US Navy would likely lose control of the high seas globally.
That neuters the factions in ASEAN who advocate closer relations with the USA and more distant relations with China.
And given that China is already the world's largest trading nation, smaller nations can understand if China wants to build a pre-eminent navy to protect its global trading interests.
From a resourcing perspective
Let's say in the 2030-2035 timeframe, China has an economy twice the size (100% larger) than the USA.
It's perfectly reasonable and affordable for China to build a blue-water navy which is 30% larger than the US equivalent.
If you run the figures, that might be possible with China continuing to spend a modest 2% of GDP on the military.
At worst, it would be a maximum of 3% of GDP, which is still significantly less than what the US spends.