Process Validation in Matrix/Bracketing

Hi, I’m one of process validation analyst for one of ASEAN Center of Product Registration. Lately I’ve come across with few Pharma company who simply completing their Product PV in Matrix. As we know, Process Validation in Matrix or Bracketting is not advisable unless it can strongly justified

Eg of those Study Design:

Product : Tablet
Strength (eg) : 10mg; and 20mg
Batch Size :400’000 tablets for each strength
Critical Process: Blending & Compression

Those company start Dispend and Blend with 400,000’s size. Then they split the batch to 2 separate group of granules.

The compression batch become smaller which is 200’000s and 100’000s.

The problem start happen because the compression validation is not replicating actual batchsize of the registered size.
They continue the process for 3 batch of granules, split it to halve and set up the stability.

I think it is a totally wrong design and it cannot be accepted unless they complete the study in the actual batch size.

Any comments?