It probably good to define the roles that each tool intends to fit, since over compromise can render good ideas impotent.
For a small tool, it's important to choose between versatility (multitool) and efficacy as a weapon (fixed or folding knife than can be concealed, rapidly deployed and has useful blade geometry). If your small tool is your primary, I think many of us would hedge our bets towards the fixed/folding knife unless we plan to work.
If the smaller tool becomes a secondary, I think it changes the dynamics towards versatility with regards to the smaller tool. For a primary blade however, I think it's hard to beat the machete as countless conflicts worldwide have shown its versatility as an edged tool and how fearsome it can be as a weapon for very little cost.