Thomas Young crossed for a second half score, but despite a grandstand finale there was no late drama as Warriors secured a first win of the season in all competitions.
"We're disappointed," said McIntosh. "We weren't consistent enough and we allowed them into the game in the first half by poor one-on-one tackling.
"Our defensive organisation was great, the collisions area was excellent and we competed very well there and made it ugly for them.
"But you can't miss one-on-one tackles and expect to win games of rugby. At half-time that was highlighted, to say the least, and we were a totally different animal in the second half.
"Youth sometimes don't understand how you have got to start quick and sustain that pressure throughout 80 minutes. Unfortunately we allowed them too many easy scores and it was tough to pull it back.
"Our attitude and intent to play in the second half was superb. But I don't settle for the fact we are a young team. If you are good enough you are old enough, you put the jersey on and you fill it with pride.
"In the first half missed tackles cost us and that was unfortunately the difference between the two teams."
McIntosh also revealed Blues would need to look at their fly half options with Gareth Davies limping off in the first half and Rhys Patchell also unavailable on international duty.
"We don't know until we access Gareth, but it didn't look too clever to be honest with the groin," he added.
"Rhys Patchell also has a shoulder knock at the moment and is struggling a touch, so the number ten position is a little vacant for us.
"Simon Humberstone filled in well today, but we need to address that and the Board and Phil will do that and see what options we have got.
"Simon is capable of stepping up, but he is not a full-time professional. He has a job so therefore he can only get better. He works hard and has great ethics.
"There is bedding in time and, in fairness to him, he has had about three training sessions and all of a sudden he is playing 50 plus minutes of rugby."