Two thoughts for (thought) leadership:
an 80% conversion rate of Leads to Closed won is pretty good, considering the CRs of Leads = > MQL => SQL => SAL => Closed Won
percentage vary based on the target market. e.g.: 80% of SMBs vs 80% of enterprise are two different things
There is no ‘shared playbook’ for sales as even within a company there are different playbooks for different markets: PLG, SMB, Mid-Market, Enterprise
I’m biased having worked for Winning by Design and Jacco pioneered a lot of this thought leadership.
To your point, a $5 mm company should only really be investing in 1 GTM motion until it has been proven to scale, it’s usually at the Series B/C when multiple GTMs are needed.
Unless you are raising a $100 mm AI series A, then it’s a total free for all 