We are the EU’s biggest trading partner. If they wish to reduce that then obviously they can, but why would they ?
Because they can afford to, yet they can't afford not to. If the UK leaves with no penalty, the EU project is doomed. The whole point of it is all partners are mutual beneficiaries. It is an existential issue for them.
Furthermore, we hurt far more from tariffs than they will due to their strength as a trading bloc accounting for a massive portion of world trade.
Our export trade with the EU is diminishing year on year while theirs grows with us. The EU is a diminishing % of world trade and has become a protectionist bloc.
We are only 65 million, yet we still have the 5th biggest economy in the world, go figure.
The 5th biggest economy counts for nothing when you notice two things - first, all the other economies we compete with are in trading blocs or are superpowers, and second, the drop off after the top four is nearly 50% in terms of GDP.
You say export is declining - debatable by the way - but even if it is, it's still in comparative terms competing with the USA and China as superpowers; whereas we are competing with France as a sole nation state in terms of size and influence, before you take into account the power they have as EU members and therefore in trade. We will be a comparative minnow on the world stage.
We will adopt a more win/win approach to world trade as opposed to the EU trying to beat down the opposition.
This is rhetoric. 'Win win approach' means absolutely nothing. We already 'trade with the world'. The difference will be that we do so currently on terms negotiated as part of a massive trading bloc able to wield influence, whereas alone we'll be taken to the comparative cleaners on terms because we're desperate. The US and China will milk us dry - they have absolutely no reason not to; they'll take every competitive advantage. You have absolutely nothing to suggest why they wouldn't apart from blind hope.
We will reinvent relationships and can be far more creative with how we deal and trade with partners as opposed to a 27/28 consensus which invariably ends up as a mishmash.
I happen to believe in the competence of our companies to trade.......
What partners? The superpowers will take us apart, as noted above - we'll be horribly desperate after Brexit, especially in a no deal outcome. The EU have absolutely no incentive to give us favourable terms after this mess, especially in a no deal outcome. Our next most traded to partner outside these is that massive world superpower known as Switzerland.
The fact is it isn't about the 'competence' of our companies, it's about leverage and realism. You can believe your players at your local pub team are competent and will always do their best, but they're still going to get utterly bladdered by Man City.