If the HMRC are too stupid to close those loopholes, then more fool them IMHO. You don't even need an exceptionally clever accountant to ensure you pay as little tax as possible, just one who has a decent understanding of the system.
If anyone ran a normal company in the way the HMRC is run, they'd be out of business within a year. They are the most incompetent, useless, awkward company to deal with, and I don't care if it's the people behind the desks or the computer system at fault tbh. Trust me, when you've got the HMRC chasing you and sending you threatening letters over a couple of grand and scaring the crap out of you, and two months after you settle up after stretching yourself thin to pay this tax bill they then turn around and say "Oh yeah, we owe you £3K, here's a cheque", you soon lose a lot of faith in them.
/VOE