In a game like Dragon Ball Online, you can only do so much to try and prevent players from running multiple clients simultaneously, and there will always be loopholes around any preventative measures that would be put in place, hypothetically.
For example, there was a period in time where players in the retail version of the game were only allowed to run 1 active client.
To avoid this, back in the day players would:
- Run third party software that would allow them to run another client
- Run the game on a secondary computer in their household
There was nothing the developers could do to stop this, and they never did punish players who were running multiple clients. You can't stop multiple clients from the same house because some people do play DBO with their siblings or friends using the same internet connection.
I do agree that a player running 8 accounts might be too excessive, as it can take up budokai spots or be used to farm in ranked matches, however, if a player leveled up another character they should be entitled to play on that character, (although so far this doesn't exactly seem to be an issue).
At the moment, every player is able to play on multiple accounts and clients, so I don't exactly see what the issue might be here, as every member is granted the same privilege.