Assuming you don't raise prayer, you'll be giving up one combat level, but maxed 50 attack 13 pray will lose it's charm, when you max out with 44/52 pray it'll keep you the same cb.
Your only giving up 1 combat level, its fine, but if you really feel like its ruined, there are still so many more possibilities for the account, zerker, initiate, addy turmoil, dharok pker, ect.
IMO 3 defence doesn't really matter at all... but I am no expert on pures. If it really bugs you that much, try questing the defence up to 45 and train the account up to become a maxed zerker, get a few chaotics etc.