Welcome to the Q&A Forum

I'd go with the umbrella brand pages. Your reservations all make perfect sense, and managing content for 10 pages sounds miserable, plus they'll all take a ton of traction to get started vs a single page. Most users are tolerant of a brand that has products they may not care about. Unless they're seriously different (like a plastics company selling kid's toys, garden equipment, and medical devices) it makes more sense to keep them together.