if you have two different dialer interfaces
with each a dialer-list permit ip any.
Is the presence of ip traffic enough to activate an interface? or does it need to pass through the dialer interface.
ip route 0.0.0.0 0.0.0.0 Dialer1
ip route 0.0.0.0 0.0.0.0 Dialer2 50
Will dialer2 interface see the traffic passing via Dialer1 as interesting traffic?
if answers is no,
will ip route (tunnel_destination) Dialer2 create interesting traffic . By the tunnel interface trying to setup IKE phase 1