Do basic math kid. If Goyo Guardian is level 6 than you gotta use 2 or so monster levels that equal 6. So a level 3 tuner and a level 3 none tuner or a lvl 4 and lvl 2 tuner. As long as it is level 6. This was just sad to see.
The problem I see is you got a Level 3 and a Level 2 EARTH Tuner. So you need a level 4 non-tuner instead of a level 3 in order to Synchro Summon with the level 2 Jutte Fighter. For synchro summoning, the conditions and total levels MUST match.