How to deal with no path when the slot to be milled is the same

Specifically, I would like to mount a 4mm and a 3mm slot cutter to a single arbor to produce a 7mm slot to house a 6mm panel Sjould I just

Cut slots and grooves for splines, biscuits, T-molding or tongue and groove joints Every cutter features antikickback design, micrograin carbide tips and

slot shaming Solid Carbide T Slot Milling CutterTiSin Coated4 FluteMade from Micrograin Carbide D1Cut DiaL1ThicknessL2Neck LengthD2Neck Dia L OALDShank Dia 6mm

lucky treasure jili slot The slots are used in conjunction with 6mm floating tenons to join timber I've also used it to cut 1m long slots to edge