Coutinho may be a flat track bully but that is exactly what we need. Someone who is going to help us get three points at home against the likes of Brighton, Palace, Southampton, etc. We don't need him showing up at the Etihad and Anfield because we losing those games with our without him. What we need is someone to help us turn the 14 draws we had last season into 7/8 wins. For this purpose, I can't think of many cheaper options on a one year loan than Coutinho.
If it's £10m for the season that it is an excellent deal. He would instantly improve us. For me the concern would be a big loan fee or potential permanent deal. Ideally we use him as a stop gap to get back in the top 4 picture. If we get it, invest in a younger big money replacement for him going into 21/22. If we miss it, go back to the drawing board and start again.