Is that 145 litres?
The pattern is not great, it's too tall for its length, but it is perfectly acceptable for a single bleheri, assam or orientalis. I wouldn't try anything bigger.
Let's be real here, I've kept most channa species, and most did not reach the sizes the websites describe, because they take the extremes. I've kept 6 bleheris in a tank that size, that I afterward moved to my 180 because I had the space, and one out of 6 reached 15 cm (He seemed like a monster compared to the others. He was a dick, too), so there was no possibility that they were stunted.
I say go for it because channas are the most amazing fish, comportment wise, they are one of those fish with personality, and I would hate if you decided to go against it on the odd chance you have a monster bleheri that reaches the extreme sizes, and to be fair, if it reaches those extremes, then it isn't stunted anyway.
As for tank mates, I will go against it. Anything people deem "peaceful" usually cause problems when the attack happens (catfishes will kill the channa with their whiskers or whatever gets stuck in the fish' throat, etc) and it will happen eventually. Bleheris are too small to be able to find a fish so small that you can put a shoal and it will not eat it. You can put a thousand cardinalis with a 60 cm wolf fish, he won't even look at them, but you can't do that with a channa.