Help needed to put some pieces together

[Marados]

In FM18, I used a few downloaded tactics (e.g. Scholes can't tackle, Sarriball revolution) at several teams. Sometimes I used them as they were, sometimes I made some minor changes, like making a CD a BPD. Now I decided to create my own tactic in FM19. My problems are: I have only some ideas for a few positions and how they should work together, but no real approach for the team as a whole. So right now, I'm feeling like Baron Frankenstein putting some pieces together and being quite uncertain about the outcome.

The ideas I've had so far:  A sweeper keeper, two ball playing defenders and two wing backs. I would have preferred full backs, but since my midfield and my attackers are all based in the centre of the field, I thought I had to give them a less defensive role to cover the wings a bit more. I love an attacking segundo volante, so that became the first position I filled in midfield. Because he needs somebody to cover his attacks, I put in a half back for defensive stability. Those two should have a good synergy. Having no wide midfielders or wingers, I decided to put in a carrilero as well, to cover at least one wing in midfield if needed. Up front, I put in a shadow striker and a false nine. Again, they should have a good synergy, with the false nine falling back and taking a defender with him, creating space for the shadow striker to push into. The last position is my biggest problem: I have no idea what to use. On the picture it's an inverted winger, but that is really only a placeholder. I thoght about another carrilero in right midfield, but I'm afraid, that he will "block" the running ways for my segundo volante, who is positioned very close to the position a second carrilero would take.

As you can see, apart from the HB/SV and F9/SS pairings, there is not much of an idea behind it, other than to come up with solutions for the weaknesses of a very centre based approach. My questions are: Can creating a tactic around the two mentioned pairings work or do I need to take a different approach, considering the team or the playing style as a whole? Do my thougths make sense at all, especially about treating the weaknesses of the tactic? And most important: Where should I put the 11th player (the IW in the picture)?

Thank you for reading, your helpful tips and comments would be much appreciated.