Comment # 2 on bug 909163 from Marius Tomaschewski

(In reply to Bill Weidman from comment #0)
> Wicked will set only one default route for the first interface that comes
> up.  Subsequent default routes are ignored

Correct. The routes have equal priority -- use different priorities/mertics.
In static case append "metric X" (or "preference X") and "metric Y" to the
another one. In dhcp case, you can also use DHCLIENT_ROUTE_PRIORITY.

See also bug 879842 and bug 879842 (and fate#312217 for policy routing).