SITE to SITE with speedfusion

I am willing to offer an upgrade to existing client to produce a failsafe site to site VPN with speedfusion & 2 Pepliink 310 X CAT18 appliances.

I understand I must buy a packet of: “Up to 30 SpeedFusion Bonding License Key for Balance 310X”.

Is this packet enough for the two units of 310x or shall i buy one license key of 30 speedfusion for each site?

My object is to fail safe connection between venues and bond the vpn traffic to increase speed and relaiblity.

The actual WAN access at each point is FIBER 600 Mbs symetric, we will add the 4G modem of the 310X as a back up at each venue to keep costs.

We expect to add AP ONE AX in near future and for inhouse WIFI and guest wifi profiting of the controller on the 310X power.

We expect to add a new WAN at each venue in future as per traffic grow.

Would it not be posibble to achieve the same with speedfusion hub/cloud?

At each venue we have 20 network clients and 15 VOIP phones.

Is it an overkill solution?