It would seem to be impossible to believe in "inescapable Fate" if at the same time holding a Celtic / European pagan world view. In the Mabinogion for instance Gwydion explains to Dylan that the world
is subject to three influences Fate, Choice and Magick, this would also seem to be the world view expressed in the other Celtic sources. A Romany friend of mine tells me a similar idea is held in Romany lore, in this lore our lives are governed by three main factors that they call in English, the luck you are born with, the luck you make and the bad luck you turn to good.
This I think is also the view held by most Witches and Magickians today, for instance after a Tarot reading tells the Fate of the person being read for, informed by the reading this person
makes Choices changing there Fate and the reader may also help with Magick, Fate is always being modified by Choice and Magick. To use the analogy of a boat in the sea, Fate is like a prevailing wind, Choice is like a rudder and Magick is the skill to use them both (maps and seaman's cunning).
Life is like a boat, Fate being of the nature of the sea currents and prevailing winds, choice the rudder and rigging and Magick the sea charts and seaman's Cunning.
Sometimes the prevailing winds and sea currents can be so overwhelming that the boat has no choice but to travel in the direction which they dictate, whether on to the rocks, some new and wonderful or wherever that might be. In calmer times the boat can to a point be navigated using the rudder and rigging, but without sea charts and seaman's Cunning these navigations are often crude and inconsistent. It is the very purpose of the boat to travel sometimes sailing a striate path and sometimes tacking a Crooked or Serpentine one and gather spiritual treasures and this needs good navigation.
Those boats without the said charts and seaman's Cunning rarely if ever travel far from shore and when they do so can be liable to hitting hidden rocks or being swept far of course and be lost.
Sometimes those without seaman's Cunning hire those who have it (Divination and other magicks).
A quick note on Magick; to continue the metaphor: Anyone with the inclination and perseverance may procure some sea charts but seaman's Cunning seaman's Cunning can only acquired through a combination of instruction and experience.
Is this not so with Magick we may purchase books but they are of limited use unless we also acquire magickal instruction (either of physical or spiritual origin) and experience, as an old magickal teacher used to say "Magick is in the doing, not sitting around thinking about it".