Don't copy the org chart of a bigger company. The first five seats depend on the founder skill mix and the business shape.
Solo technical founder building SaaS — first 5: (1) hands-on engineer, (2) customer-led marketer/content lead, (3) head-of-sales-shaped operator, (4) second engineer, (5) customer success / support.
Two-person team building services-shaped SaaS — first 5: (1) account executive, (2) implementation lead, (3) second engineer, (4) marketer, (5) ops coordinator.
Solo non-technical founder — first 5: (1) technical co-founder (this is hiring #0, not hiring #1), (2) early engineer, (3) yourself in sales until $1M ARR, (4) content/marketing, (5) success/support.
Common pattern across all of them: sales-shaped person within first 3 hires. Marketing-only first hires usually under-perform because marketing without a sales-feedback loop produces volume without revenue.