I think it's pretty safe to say that this guy is the weakest of all the British commanders. I know there have already been quite a few threads about this, but they focus mainly on the Sexton. Instead, I want to go through the commander as a whole.
So what have we got?
Early Warning
3 CP, 60 munitions, 30s duration
This ability is good. Lights up enemy frontlines for a reasonable price. Not much else to say really.
Concentration Barrage
4 CP, 100 munitions
This ought to be the core ability of the doctrine, but the restrictions on it kill it entirely. To use this ability you have to have line of sight, pay 100 munitions (sections flares are 45 per use by comparison) and each gun will only fire 3 shells as opposed to 6 fired when section flares are used. Also comes with a big red "I'm firing here" flare.
When the game launched it could be fired without line of sight - allowing the base howitzers to be used like an ordinary howitzer with the exception that other howitzers don't give a big red flare to warn the opposing player. Combined with anvil it could be used an accurate counter to ISGs and the likes, but was munitions intensive. Without explanation or even a patch note it was changed to require line of sight - which begs the question "why would I use this instead of section flares?", especially given that the section flares barrage is cheaper and better.
Even when blind firing in the past, Anvil was more or less required to make it worthwhile. The base howitzer shells have the worst possible dispersion for a howitzer, and their AoE is small to say the least. A direct hit is required to do anything and even against stationary OKW trucks you couldn't rely on shells hitting them without airburst.
I would suggest that the line of sight nerf be reverted to give the doctrine back one of its key pieces.
EDIT:
As of the February patches, Concentration barrage can now fire into the fog of war again! This is a massive improvement and almost makes the ability viable again. Problems remain due to the 25 pdrs being generally unimpressive, the high expense relative to tommy flares for half the shells fired and anvil being more or less required to get mileage out of it.
Valentine
6 CP, 300 MP, 80 Fuel, 12 Pop
Any time I've seen this used, it has essentially just been a fog of war scanner. I've never found it good against inf, and at 80 damage its main cannon is pretty weak against anything but light vehicles. Indeed it seems worse at combat than the cheaper (340/50/8pop), non-doctrinal AEC which does 120 damage.
It's also the only unit I can think of that requires another specific unit for its vet 1 to do anything at all.
Sexton
9 CP, 375 MP, 90 Fuel, 14 Pop
There has already been a ton of discussion on the Sexton and why it's just plain bad, so I'll simply link a few for now:
http://www.coh2.org/topic/44942/i-m-surprised-they-didn-t-buff-trash-sexton
http://www.coh2.org/topic/41457/the-sexton-sucks
http://www.coh2.org/topic/43619/sexton-underperforming-for-cost
http://www.coh2.org/topic/43672/ukf-sexton-stats-comparison-buff-needed
http://www.coh2.org/topic/43429/the-valentine-and-the-sexton
Perimeter Overwatch
10 CP, 225 Munitions, 2 minute duration
All this ability effectively does is turn your map sectors orange and eat munitions. Assuming even perfect sight, you have to wait for the base howitzers to turn to target and by that time the point can be decapped so nothing will happen anyway. Assuming it does get a volley or two off, it does little to deter or wound an attacker since the AoE on 25 pounder shells is so low and the accuracy bad enough that hitting anything at all is pure luck. For this to be useful at all the base howitzers need to turn a bit faster.
Really, the main problem is that the artillery the entire doctrine is based around simply isn't good. Low area of effect and splash cripples both the base howitzers and the Sexton. It simply isn't worth giving up units like commandos for artillery that's too random to have an effect. Likewise if you want to use artillery to clear entrenched positions, you're better off using the Concentrated Artillery Operation from Special Weapons Regiment.
I'd also say that the Valentine and Sexton seem to be balanced around the synergy between them - but as a result neither are useful. A higher cost, better Sexton would make the synergy harder to obtain - but it would actually be worth doing. A combat capable Valentine would mean you might actually get vet 1 to use it in the first place. Both being viable would also mean sinking your pop cap into it wouldn't be suicide.
Anyway, that ended up longer than I thought it would but I do think this commander badly needs looked at.