Ok, as I se You still dont understand. If You want to use Your (custom) splash screen do what CE told You, but...
If You want to use ONE screen - while each L2.exe start will be showed one ONE type of splash screen You need to edit whole splash screen from systexture (from _01 to _10 - for chronicles to CT2.2, and from _01 to _12 for chronicles from CT2.3 and newer) and make them look the same...
Got it ?
Bye