Mia taktiko ne estas tiel simpla kiel via strategio.

They actually already have the adjective-type ending built into them.

• mia = my
• via = your

Possessive words in Esperanto usually look like correlatives or pronouns turned into adjectives, and they behave like adjectives. That is why they can describe nouns directly:

• mia taktiko = my tactic
• via strategio = your strategy

If the noun were plural or accusative, these words would usually match it:

• miaj taktikoj = my tactics
• viajn strategiojn = your strategies as a direct object

So mia and via are already in the correct form here.

Because -o is the normal noun ending in Esperanto.

• taktiko = a tactic
• strategio = a strategy

In Esperanto, part of speech is shown very clearly by endings:

• -o = noun
• -a = adjective
• -e = adverb
• -i = infinitive verb

So the sentence is easy to parse because both taktiko and strategio are marked as nouns.

Because simpla is an adjective, and adjectives in Esperanto end in -a.

Here simpla describes taktiko, so it must be an adjective:

• simpla taktiko = simple tactic

Compare:

• simpla = simple, as an adjective
• simple = simply, in a simple way

So in this sentence, simpla is correct because it describes what kind of tactic it is.

tiel ... kiel is the standard Esperanto pattern for comparison of equality, like as ... as in English.

So:

• tiel simpla kiel = as simple as

In this sentence:

• ne estas tiel simpla kiel ... = is not as simple as ...

This is a very useful pattern:

• Li estas tiel alta kiel mi. = He is as tall as me.
• Ŝi ne kantas tiel bone kiel sia fratino. = She does not sing as well as her sister.

So tiel sets up the degree, and kiel introduces the comparison.

Because ne negates the verb phrase.

• estas = is
• ne estas = is not

So:

• Mia taktiko estas tiel simpla kiel via strategio. = My tactic is as simple as your strategy.
• Mia taktiko ne estas tiel simpla kiel via strategio. = My tactic is not as simple as your strategy.

In Esperanto, ne usually comes right before the thing it negates, and very often that is the verb.

In practice, the whole statement is negated through the verb: is not as simple as.

Esperanto normally handles this the same way English does in this kind of sentence. You do not usually analyze it as not simple, but rather as not as simple as. The comparison pattern stays together:

• ne estas tiel simpla kiel ...

So the meaning is that the speaker’s tactic has a lower degree of simplicity than the other person’s strategy.

Because Esperanto does not use the definite article as often as English, and here it is not necessary.

• Mia taktiko already means my tactic
• via strategio already means your strategy

The possessives already make the nouns definite enough in context. In fact, using la together with mia or via is usually unnecessary in ordinary sentences.

So mia taktiko and via strategio are perfectly natural without la.

The given word order is the most natural and straightforward:

• Mia taktiko = subject
• ne estas = verb phrase
• tiel simpla kiel via strategio = complement with comparison

Esperanto word order is fairly flexible because endings show grammatical roles clearly, but not every rearrangement sounds equally natural. This sentence in its current form is the most normal way to say it.

You might change the order for emphasis, but a learner should usually stick with:

subject + ne + verb + complement

Because after kiel, Esperanto often allows a shorter comparison phrase, just like English.

• tiel simpla kiel via strategio = as simple as your strategy

The full idea is something like as simple as your strategy is, but Esperanto does not need to repeat estas here.

This kind of ellipsis is very common and natural.

They are very close in meaning and form, since both come from international vocabulary.

• taktiko ≈ tactic
• strategio ≈ strategy

That makes them easy for English speakers to recognize. Still, it is worth remembering that Esperanto spelling and endings regularize them:

• English tactic → Esperanto taktiko
• English strategy → Esperanto strategio

So they are familiar, but adapted to Esperanto word-building rules.

Then the nouns and matching adjectives/possessives would also become plural.

For example:

• Miaj taktikoj ne estas tiel simplaj kiel viaj strategioj.

Changes:

• mia → miaj
• taktiko → taktikoj
• simpla → simplaj
• via → viaj
• strategio → strategioj

This shows one of Esperanto’s key rules: adjectives and possessives agree with the nouns they describe in number, and also in accusative when needed.