There should be a leader's benefits/advntage than being regular member. Aside from promotions and mails no more than that?
Here are some ideas:
1. Maybe during wars leaders baracks (even 1 rak) will get an automatic boost. Because basically its leaders responsibilities to donate for clan members during prep and war day.
Or
2. Extra loot bonus during war
Or
3. Has lesser training time for his troops during war.
Even 1 from these ideas or similar will do sure get leaders become happy. After all, they do all the management thng on the clan so its only right to compensate it with something right