In general for the majority of teams/tactics, using a "big man/little man" combo will work well. Have one of your tall, strong strikers be a target man or deep lying forward, and set the faster one to poacher or advanced forward.
If you use target man striker (I'm talking about the ROLE here, not the team instruction), deep lying forward (support), or complete forward, he must have high strength. No striker with low strength should ever be one of these roles (including complete forward) due to the "hold up ball" instruction. If your best strikers have low strength then you can just use advanced/poacher or advanced/advanced.
Sorry if that's not what you were asking, but it wasn't totally clear to me what you meant. If you were wondering if it's ok that your team's target man (in team instructions) has a different role than "target man", yes, that's perfectly ok.
