Erm.... If it wasn't for the arrogance of Johnson, there wouldn't be a Ukraine anymore and we would be facing a whole new sh*tshow with Russia still fully manned and equipped sitting on the borders of the likes of Poland ready for part two.
It was Boris that pushed the West into helping Ukraine when no one else would listen, we helped train the Ukrainian army with other allies to be a competent, professional and Western oriented force far removed from what they previously had before the Russians attacked and provided them with NLAW's that in their part blunted Russia's ambitions and forced a withdrawl from the likes of Kyiv.
Yes, an all Leopard force would be ideal, but in supplying them it was part political to embarass our European partners into opening up to the idea of supplying modern tanks by breaking down that red line, and in part a Challenger is an excellent tank, superior to most of the Russian tanks fielded and in a war, every little helps.. to paraphrase a well known store.
Like him or loathe him, at the end of the day he has secured his part in the History of Ukraine and the West, without his timely interjection the world could well have been a different place in Europe, and not for the good.