How many Croct slots do I need for a homepage with several personalized blocks?

Scoping a Storyblok homepage where three blocks would be personalized: the hero, a promo strip, and a testimonials block. Before I commit I want to understand how blocks map to slots and how that lines up with plan limits, so I can size this correctly.

Concretely: is it one slot per personalized block, and how does that count against a plan's slot allowance? Trying to avoid a surprise when I pick a tier.