With this account there is no problem. But you should go buy new athletes and go reshaping the team.这个账号没什么问题,但你需要买新的运动员并重组队伍.
If you want to start with another account was reassigned all athletes, but you will have less money than you have now.
如果你想以新账号开始（玩游戏）,你将会配得所有运动员,但你的钱将会比现在的少.
不是你理解的问题,是管理员的英语不通顺：If you want to start with another account was reassigned all athletes, but you will have less money than you have now.
这句话应该写成：
If you want to start with another account,you（或which) will be reassigned all athletes, but you will have less money than you have now.
1.为什么有IF.but的句式,他想说明什么?答：这不是什么句式,but只是一个转折.
2.account was reassigned 为什么不加which.答：这是管理员的错误,是他对付你时没有主语语法,只是像和你聊天,不太讲究语法.
3.start with this account 和start with another account 有什么不同.答：this account是你原有的账号,里面因为你以前玩的成绩,赚（赢）了一些分（钱）,another指你新开的一个账号,只有系统标准配置的钱+运动员等.
【但愿你理解正确.】