Why wider landing gear would not create a naval Tornado

Could Tornado's wide landing-gear track be strengthened with only minor changes for carrier use?

No; the shock loads must be carried through the surrounding airframe, so a credible conversion would require extensive structural redesign.

The follow-up suggests that Tornado's relatively wide undercarriage might leave room for a stronger carrier arrangement. Track width is only part of the problem. An arrested landing sends a severe shock through the gear and into the structure that supports it, so load paths and energy absorption must be designed into the airframe. Strengthening those areas after the fact would require rebuilding much more than the wheels and struts. Visual similarity in landing-gear layout does not establish that two aircraft are equally suitable for carrier conversion.