To me, 38 sports would be fair. In addition there should be around 400 events, as Singapore had 402 events.
Another principle is that other SEA Games countries should be given the opportunities to excel in some sports they are good in.
In other words, countries with limited chances to win medals should not see the sports and events they are good at be dropped, thus depriving them a fair chance of winning some medals.
If the objective is to restrict Thailand from winning too many gold medals by deleting some sports and events they are strong, the Organising Committee should not do the same with sports and events in which the other SEA Games countries (other than Thailand) have chances of winning medals.
This is more so in the case of Indonesia and Philippine, the next host of the 2018 Asian Games and the 30th SEA Games in 2019.
The Organising Committee has approved 34 sports.
From the above list of 34 sports, the NOCs of Cambodia, Laos, and Vietnam will probably not be participating in the following 12 sports, namely, Cricket, Equestrian, Hockey, Ice Hockey, Ice Skating, Lawn Bowls, Netball, Rugby 7’s, Sailing, Squash, Tenpin Bowling, Water Ski and the following disciplines Synchronized Swimming, Open Water Swimming, Water Polo, and Track Cycling.
Myanmar and Brunei Darussalam will most probably not be participating in the above 12 sports, with the exception of Equestrian, Hockey, Sailing, Netball and Squash and the following disciplines Synchronized Swimming, Open Water Swimming, Water Polo, Track Cycling and Polo. Brunei will participate in Lawn Bowls.
Philippine will probably not participate in Cricket, Hockey, Lawn Bowls, and the following disciplines Synchronized Swimming, Open Water Swimming and Polo.
Indonesia, Singapore and Thailand will probably participate in all the above 34 sports, but may miss out some disciplines, such as Track Cycling for Singapore.
The sports/discipline that may face limited participation are:
Track Cycling – only Thailand, Indonesia, Philippine and Malaysia have veladrome. If any two countries were to drop out from any event, that event would be dropped, as minimum of 3 countries are required.
Lawn Bowls – Brunei Darussalam, Thailand, Malaysia, Singapore and may be Philippine will participate.
Hockey – Myanmar, Thailand, Malaysia and Singapore. The Indonesia Hockey Federation is still suspended by the Indonesia Olympic Committee. Brunei may participate although most unlikely.
Ice Hockey and Ice Skating – so far, Thailand, Malaysia, Indonesia, Philippine and Singapore have indicated their interest to participate.
Netball - Brunei Darussalam, Thailand, Malaysia, Singapore, Myanmar and Philippine
The Organising Committee has dropped a number of sports that are popular with most of the SEA Games countries. These sports are Fencing with 10 countries and 87 male fencers and 71 female fencers and Judo with 9 countries and 43 male athletes and 39 female Athenes