2ZZ-GE eating rod bearings

So here is the back story to my problem,
I recently purchased a 2000 Celica GTS for dirt cheap, in great shape, but it had a rod knock. I towed the car home and pulled the motor. After getting the engine apart I found the #4 rod bearing completely gone and the crank journal WAY undersized. I took the rods, crank, block and head to a local machine shop for some reworking. The spun rod was junk and needed to be replaced. The crank had the spun journal welded and then reground. All 4 pistons were replaced. The head was completely rebuilt and the valves adjusted. The block was cleaned, decked and pressure tested. I got everything back and it all went together great. Got it in the car and noticed my first issue, no lift. after replacing both OCVs, VVT cam gear, and both VVT filters the only new development was more rod knock. Pulled everything out and apart to find the #4 bearing eaten up. I took everything back to the machine shop and they said the replaced rod wasn't sized properly, They polished the crank resided the rod and I was off to put it all back together. With the motor in, everything runs smooth but I still don't have lift. After losing my mind for 2 weeks not able to figure out my lift problem, thanks to a thread on this forum I found the problem. The machine shop swapped the intake and exhaust rocker shafts. None of the oil hole lined up and hence, no lift. The shafts had been beaten into place and were an absolute pain to remove. I finally got them out and after some polishing, I got them back in. Now I have lift.... and a rod knock.

here is my problem,
Is there any reason this motor would keep eating the #4 rod bearing? other than scoring caused by the #4 bearing parts going through the oil system, the other bearings look great. Just the #4 bearing is completely toast. When the engine was assembled EVERYTHING was completely cleaned measured, and lubed, I don't see anything blocking oil passages, and sealant was used sparingly. Is there any way the swapped rocker shafts could have some how been part of my problem? I am going to find a different machine shop tomorrow and have them check out the rod and crank. I'm in the long beach L.A. area of CA. if you have a shop to suggest.
Any help would be great, this is starting to get expensive and tiring.