The personality number comes from consonants alone — the part of your name that, numerologists argue, carries the structure while the vowels carry the feeling. Reduce those consonants to a 4 and the tradition offers a portrait that's less about sparkle and more about solidity.
Where a 3 walks in talking, a 4 is traditionally described as walking in having already checked the exits, the schedule, and the fine print. It's a useful first impression to have on a team. It's a harder one to soften at a party.