Failback with 2 WAN interfaces


I have a little special question so let mi give you my setup:
I use a PC as a router with a 4 port Intel NIC as a switch, I have a QWA-AC2600 as Wifi, I also have a Alfa Network AWUS036NHA on USB and a Huawei E3372 LTE Stick.
I use the Alfa to connect o my Smartphone hotspot as WAN, I also use the Huawei as WAN.
Is it possible to configure the two as failback for each other? The Alfa should be main WAN interface but if I leave and take my Smartphone with me it should activate the Huawei stick as WAN.

Thank You

You need mwan3 package