Sorry. If you’re using liquid yeast you make a starter. Even at low OG. The amount of active yeast in the pouch is dependent on so many things - transport of yeast to supplier, storage of yeast by supplier, age of yeast. Then you also need to focus on if you have a pitchable amount and did you provide enough dissolved O2 in the wort. Dry yeast are packaged with glycogen and other nutrients to assist in lag time and fermenting, while having more ‘active yeast.’ Liquid yeast is a different animal.
Reasons to make a starter:
1) wake up the yeast for low OG
2) build up enough yeast slurry for a pitchable amount per OG
This is why I’ve moved to dry as much as possible. Dry yeast quality has really come a long to the quality of liquid yeast. Dry yeast EASILY provide more active, healthy yeast population. It’s cheaper than buying liquid yeast, DME, then continuing to build that up for an appropriate pitch. It’s much easier. It’s easier to store. You can store it for MUCH MUCH longer.
The ONLY time I use liquid yeast if there is no dry yeast equivalent or I’ve tried the strain and it just isn’t up to par with a liquid strain.