Zaid Alsalami, Shaykh Dr Zaid Alsalami is an Iraqi born scholar, raised in Australia. He obtained a BA from Al-Mustafa University, Qom, and an MA from the Islamic College in London. He also obtained a PhD from... Answered 1 month ago

Bismihi ta'ala

You will not be able to do both wudhu' and ghusl simultaneously and at once. 

So, you can either do wudhu' before ghusl, or after ghusl. 

When you wipe your head during wudhu', you can use four fingers, or three fingers. Both cases are fine.

And Allah knows best.