Would this only be a problem if they vest in non-uniform quantities? At the company (Shopify) I work for they vest in even amounts over 4 years but you have to

Would this only be a problem if they vest in non-uniform quantities? At the company (Shopify) I work for they vest in even amounts over 4 years but you have to wait 1 year to get 1/4 of them then every quarter after that.