question: FSE doesn't always compress better than huf - expected?

I can't share the data, but in short, it's 9108363519 bytes (~9GB) of almost-uncompressible data (IIRC it's the 9GB tail of a larger already-compressed stream).

% ./fse -e ./almost-uncompressable
Compressed 9108363519 bytes into 8992064047 bytes ==> 98.72%
% ./fse -h ./almost-uncompressable
Compressed 9108363519 bytes into 8943423537 bytes ==> 98.19%
% ./fse -z ./almost-uncompressable
Compressed 9108363519 bytes into 8944678105 bytes ==> 98.20%

Granted that I don't know the intimate details of FSE and this is a near-pathological case, but I'd have expected the two huffman implementations to fare rather worse than FSE on these almost-but-not-quite-uniform distributions of data.

Am I wrong?

Cheers.