Four kilometres was just too far for Orakha to detect his existence, even if he weren't in disguise and hiding his presence to the utmost level. Inala was simply being cautious, since Orakha had more time to develop in the Brimgan Empire.
After they met at the entrance to Guna Caves, Orakha made a beeline to the Brimgan Empire. In contrast, Inala went to the Dralh Sea and spent a lot of time there for his plans.
Therefore, it wouldn't be surprising if Orakha had a large team working for him already.
Inala had Orakha's memories, through which he knew that the latter was talented in the way of commerce. The Brimgan Empire was the perfect place for his strengths to shine. So, even a few months of lead would be enough for Orakha to make significant preparations.