Basically a similar format to what Zeio has posted but rearranged to:
1. Incorporate doubles in the first tie to emphasise its importance (and enhance the role of weaker players) as ITTF intended
2. Add an element of unpredictability in the 4th and 5th ties for spectatorship. Right now all ties are determined the moment teams submit their lineups, but allowing for 4th and 5th ties to be decided after accessing a team's performance in the first three ties would be a talking point for spectators as well.
Proposed Format:
Doubles (A/B)
Singles (C)
Singles (D)
Singles (A or B)
Doubles (any configuration of players who did not play in tie 4)
To illustrate my points, I'll use players from the current Japanese women's team since this is where the thread is posted, while possibly drawing on other nations/time periods where necessary.
a. This will force teams to make a decision: Do you want your best player to be featured in 2 matches within the first 4 ties? If yes, then she may only play the fourth singles if the rest of the team is able to win at least one point (or if she's good at doubles). If they insist on sending him to singles, the team has more flexibility in deciding where she plays (2nd or 3rd tie).
Ito/Hayata
Hirano
Ishikawa
Ito
Ishikawa/Hirano
OR
Ishikawa/Hirano
Ito
Hayata
Hirano
Ito/Hayata
b. This flexibility allows the Sato-problem to be fixed. 1 out of 4 players will only play one tie and this will allow teams to field defenders more easily without having to think about fielding them in two singles that locks the rest of their lineup.
Hirano/Ishikawa
Ito
Sato
Ishikawa
Ito/Hirano
c. The player that only plays one tie may be 'hidden' in this format by allowing them to play in the first tie only. This spot may serve to introduce inexperienced players to big tournaments, or to protect players that are deemed ineffective against the opposing team while still allowing them to play (e.g. Ishikawa against China)
Ishikawa/Hirano
Hayata
Ito (ties 2 and 3 swapped from previous examples to highlight the flexibility again)
Hirano
Hayata/Ito
d. Alternatively, a player that has not proven themselves in singles but has had exemplary records in doubles may be fully utilised in this team format. I believe this was why ITTF introduced doubles into the olympic format as well in order to keep the event relevant since doubles events were scrapped after 2004.
Sayaka/Fukuhara
Ishikawa
Ito
Fukuhara
Sayaka/Ishikawa
Teams with only one or two strong players are heavily penalised in this format. While the current and previous olympic formats are less problematic in this aspect, the WTTC team format is prone to being a one or two man show as 80% of the fixture is covered by two players only. This has allowed many teams to get away with fielding under-developed players in the third fixture while still achieving good results.
The most obvious example here is the Singapore women's team, which still lay within the quaterfinals/bronze medal range for much of 2013 to 2016 despite having only Feng Tianwei and Yu Mengyu as reliable players. In this alternate format, the only way Feng and Yu can cover 3 fixtures for Singapore to win a team match is if they allow the match to go the distance:
Yee/Goh
Feng
Yu
Yee
Feng/Yu
Any other configuration would see Feng or Yu paired up with a weaker team member in the final doubles fixture. I believe this will send a strong message to other nations to focus on developing players outside of their core team as well. Other offenders that have either coasted with only two strong players or have stuck with the same core team of 3 for many years and thus prevented their non-core players from getting exposure include
Romania, Netherlands, South Korea, Austria
There's a lot more that can be said about this, but one thing I wanted to add was that I'd much rather watch a doubles pair win the final tie than a single player become the 'hero' of the entire match. In fact, the entire reasoning behind this proposed format is to make all 5 ties equal in terms of magnitude and importance while eliminating the possibility that a team may win (or lose!) an entire match when one of their players has won two singles matches. In this format you won't get a repeat of the 2016 Olympic semifinals where Ishikawa won two singles matches and still had to taste defeat because the only way to win two matches is to win your singles tie on top of the doubles tie with someone else (other notable instances:
Kim Kyung Ah vs Japan, WTTC 2010; Feng Tianwei vs North Korea, WTTC 2016)
More of such scenes could be possible maybe?
