You will be missing out on so much exploring like this. Do you intend only to visit the capital/popular cities? I would suggest you select Singapore+2 countries of your choice and explore.
If you are headed to Thailand, do not miss out on the islands. Just 1 day in Krabi is absurd and 7 days in Bangkok is overkill. I'm not sure of the rains, but if it is possible to go, do not miss out on Northern Thailand. Chaing Mai and Chaing Rai are just spectacular with so many interesting temples.
If you go to the Philippines and visit only Manila, you haven't seen the Philippines. I'd include beautiful places like Coron, Palawan, Boracay, Bohol, etc. Just do a quick google search and you'll know what I mean! Phillippines has one of the best waters in the world and is one of my favourite countries.
