Working on Strategic Workforce Plan for Digital Manufacturing area, I would like to get your contribution, especially in bioPharma environment, to design the local IT teams: -  What are the ideal size (headcount/consultants)?   - Ratio between internal/external resources - Main skills or capabilities.

Everyone will say "It depends" There are two factors that you need to consider when looking at this. 
1: What is your on-premises to cloud hosted ratio? The less on-premises infrastructure you have, the fewer people you need on-site. Most back-end infrastructure can be managed remotely so you won't need people on-site to do that. You will need network infrastructure engineers, and some help desk people on-site though. Anyone that will deal with the physical infrastructure, racking servers, running cables, or helping manage laptops, phones etc. 
If the network goes down, your centralized back-end support can't support the kit. 

2: Tooling and knowledge bases for the local service desk. If you don't have the right management tooling, your people can't scale. So, you'll need to look at things like your service desk support ratio. 1 service desk person can support between 30 and 100 people depending on if they have the right tools, and the right knowledge base at their fingertips. But if you are relying on the person's individual knowledge, you will have a ratio close to 1 to 5 and you'll need more service desk people. 

Well that is an enormous question.  Of course, the answer is "it depends".  The ideal size of the team according to the CFO is typically 0 (zero).  Team size will be a function of complexity of business, functionality availability, novelty of business model and disruption expectation.  Rank each from 1 to 10 (1 being low, 10 being high), add the four factors, divide by 4 and assume 5-10 people per point.  Now as to assigning internal to external,  The closer your factors are to 1, the more you should lean on external as your business is fairly generic and there should be penty of marketplace resources at your disposal.  

Finally, capabilities.  We are in a time of decreasing information asymmetries.  That means the value is not in solution identification, but in problem identification.  I'd prioritize creative thinkers that are internally driven and naturally collaborative.  On the technical side, the closer you are to 1s - the more you should look for the IT equivalent of "quilters" (IT quilters) that have a broad experience with SaaS and PaaS offerings and are used to stitching existing components together.  If you are closer to 10s, look for "IT weavers".  People who are hands-on keyboard and know how and where to generate code - preferably with plenty of experience in Generative AI coding tools like GitHub Copilot.  They should also be familiar and experienced in true DevOps processes (not simply "Agilefall" waterfall projects that were put into Jira and therefore MUST be agile, right).

Let me know if I can be of further assistance.