Yes, yes it does. You can level a 4* from 1-1 to 4-70 faster than a 5* from 4-1 to 4-80.
And that’s without the wait time for the 4* mats.
You are better off concentrating on the 4* until you have a solid core of them to use.
You do realise it would be more effective to level the costume on your already-maxed Kashhrek than to raise another one at this stage? I don’t believe anyone needs more than one Kashhrek…
I also would advise to lvl 3 and 4* first x 6
You have lots of good 4 Griffin, Fura I use a lot due tournaments. Healers of different colours should be definitely priority for the war especially