As people said earlier Celeron G3900/G3930 is enough
Once I bought Pentium for my rig and... well it runs a little bit better... but that's not required
You did well. Having a bit of more horse power under the hood can never hurt especially when the price difference between these 2 processors is a mere 15 EUR.
Keep in mind that you cannot run more than 6 GPU-s with only 4GB of DDR4 ram, for 12 or more you need at least 8GB of ram. Do not forget also to change virtual memory to 17000 and 34000 MB in advanced system settings, above 4g enabled and all PCIEX set to GEN1.
This is the perfect configuration in any specific mining board like this one ASROCK H110+ PRO BTC.
Do not forget to update BIOS of mobo to latest version as well.