score:11
A visa is permission to enter a country.
Where you're coming from doesn't matter. If you have a visa permitting you to entry country x, you can arrive in x from any other country. (There are restrictions on ports of entry for some travel between India and Nepal, and sometimes other country combinations, but that's not asked-about in this question.)
It's worth noting that in the current time of covid, there are often covid-specific requirements as well: while some countries in the recent past refused entry to travelers who've been in other, specified locations during the past days or weeks, those prohibitions have disappeared. Many countries do, however, require travelers to show proof of vaccination or to quarantine. A reputable source for such travel information is Sherpa. Both Singapore and Malaysia require quarantine if the traveler is unvaccinated.
Upvote:2
Some specific answer for this itenary.
Yes, you are allowed to enter from any country, provided your visa rule allows that. I have travelled 7 countries successively once and there was no issues.
Regarding your itenary, you can take visa as follows.
Some tips.
Happy journey.