Yes the valve stem seals are a known problem. If you are sure the seals haven't been done, you probably are OK in doing just the seals. If the seals have been done once, usually the next time it will need guides, just as a general rule. You do want to do a simple "wiggle test" on the stems to check for any excess looseness (worn guides) any time the seals are removed.
You can do just the seals with worn guides but the seals won't last very long, if it is bad enough you will be right back where you were after only a few oil changes (10-20,000 miles at the most)

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My 190E 2.6 (m103) had bad compression in #2 and #4. Pulled out the head, sent it to machine shop, and did head job w/ new guides, new seals and new valves (as well as a new head gasket).

All cylinders now have good compression, 185 psi.

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